The perfect plate of food: seasonal and well seasoned

How to cook food that's healthy for us and the planet without compromising on taste...
22 August 2023
Presented by Chris Smith
Production by James Tytko.


this is a picture of a chopping board full of vegetables


Eating. We all have to do it 3 times a day and there's a lot to consider every time we do: is what I'm eating good for me? Is it sustainable for the planet? Can I afford the time or the expense to prepare it? In this episode, we address all these concerns, but with a focus on why food brings us joy in the first place: taste and flavour! Join Chris as he embarks on a culinary challenge to achieve everything he wants from his dinner, without compromising on cooking something delicious. The adventure takes him to a top Cambridge restaurant, to hear how a local chef is making tasty dishes with locally sourced ingredients... 

In this episode

Roast turkey dinner

01:41 - What makes great food so enjoyable?

Taste is to help with survival, while flavour is what we savour...

What makes great food so enjoyable?
Charles Spence, University of Oxford

What makes food taste good? Speaking with Chris Smith was Charles Spence, experimental psychologist (there’s a clue) from the University of Oxford…

Charles - So the exact number of basic tastes that we can pick up in the tongue and in the oral cavity isn't quite known, but there are four or five at least that everyone agrees on, and those would be sweet, sour, salty, bitter and the proteinaceous taste of umami is a mysterious fifth taste from the East. And those are designed to enable us to decide which foods are safe to eat, that it may be nutritious, and which ones to avoid because they may be poisonous. And we're all born liking sweet tasting foods because of the calories they may contain. All newborns of humans, rats and chimpanzees are born sticking their tongue out and down, trying to eject anything that tastes bitter because that's a fairly good sign - of course not perfect - that what we've put in our mouth might be poisonous. Salt, we like more or less depending on our need state, to get the minerals, and then sourness and acidity people aren't quite sure what that's doing.

Chris - So if I wanted to design a food or cook something, which is going to really tantalise my taste buds and attract me for all the right reasons, what sorts of flavours or tastes should I go for? How should I try to make that food appealing so I want to eat it?

Charles - So while in a way our taste buds are at the ultimate arbiter of what is safe or perhaps not safe to eat, I think most of what we think of as taste or as the flavour of food really comes from our nose, from the orthonasal sniffing - when we sniff, like the Bisto kids, the aromas of foods out there cooking on the stove or in the store or elsewhere. And then the retronasal sense of smell, whenever we chew and swallow food or drink, it's going to pulse a volatile, rich scent pushed out of the back of the nose. And that is really where most of the pleasure of food comes from. That's where things like the nutty, the meaty, the floral, the herbal, the fruity, all those things that we might enjoy and savour in food are really being delivered by the nose, not by the tongue or the mouth. They only give a sweet, bitter, salty, sour, umami sense. So I'd be really trying to think of a food that has a really appealing aroma.

Chris - What about the visual as well?

Charles - I think that's absolutely key too. We've long said that we eat first with our eyes and all of the research shows that our brains very rapidly will process a scene, figure out if there's anything worth eating out there. And in particular, if it's highly energy dense, our brains will attempt to follow, keep track of that in case we can eat it a little bit later.

Basket of vegetables

04:42 - Cooking tips from Mill Road's Masterchef

Uncovering the scientific-like process underpinning experimentation in the kitchen...

Cooking tips from Mill Road's Masterchef
Alex Rushmer, Vanderlyle & Alice Guillaume, Cambridge Food Hub

Chris was looking for a healthy, planet-friendly but delicious meal. Not being a cook, though, he needed some help. Luckily, he happens to know a former Masterchef finalist and went to see him...

Chris - So here I am on Mill Road in Cambridge and I'm outside Vanderlyle. This is the restaurant of Alex Rushmer, my go-to person whenever we have a food related quandary or challenge. So let's go in and see if he can help us. Hello Alex. Good to see you. It's been a while actually.

Alex - Pre pandemic. A lot's changed. I think we've both aged probably about 15 years.

Chris - Now you are my go-to person whenever we have a food related challenge and I've been set a challenge. We vaguely outlined this when we agreed to meet, but we're doing a programme about how to make food that a person wants to eat, so it's nice and tasty, but also is healthy for them and critically is also healthy for the planet. We're trying to eat better in all respects. And it suddenly occurred to me that that is essentially what you were trying to do, your key aims when you set up Vanderlyle.

Alex - You've absolutely nailed it. First and foremost, we want to cook tasty food. Really tasty, delicious food that's reasonably healthy. I don't want people to roll out of here feeling overstuffed and full of heavy fats and proteins. So we focus on vegetables, but also food that's in season, food that's locally sourced where possible. I'm not too dogmatic about it, but locally sourced if and when it makes sense. So that's it.

Chris - How easy is it to meet those obligations in terms of getting the produce that ticks the boxes you want to tick? Is that easy to do and run a viable business?

Alex - I thought this was going to be a real challenge, but we made it much easier for ourselves by only focusing on plants. So we are able to tick an awful lot of those boxes by cooking a vegetable focused, vegetable centric menu. And that's not to say we're a vegetarian restaurant because that's not part of our philosophy, it just happens to be almost coincidental.

Chris - We did cook a chicken here once.

Alex - We did cook a chicken. It never made it onto the menu. But having that as a challenge and having those restrictions, I think, has made my cooking better and made it more interesting and made it more sustainable and made me think much more about the process. If you think about the foundations of classical French cooking, it's all meat based and stock-based and fish based, we had to throw all that out. We couldn't rely on those things. So we had to find ways to create those deep flavours, those textures, those satisfactory dishes and meals and menus without being able to use any animal protein.

Chris - It must be a bit like science in many respects when a scientist has a hypothesis and then they start doing experiments. Do you do food experiments to try to come up with different ways of cooking stuff and different combinations in order to make exciting things that I would want to eat?

Alex - Experimentation is really crucial to what we do and as you say, we begin with a hypothesis and for us that is the concept of a dish. And sometimes it's instinctive and sometimes it's based on empiricism and sometimes it's based on just some loose idea of a dish that we think might work. And then we go through a process of cooking and refining and changing and altering and often over the course of a two or three week period, a dish, even a dish on the menu, can change in incremental ways depending on the produce that we have available to us and depending on the cooking techniques. I think a good example is probably a chilli that we have on at the moment, which is made from strawberries, which sounds completely crazy, but we'd had a strawberry ragu on the menu for quite a long time and there was one morning when we came in and we said what would happen if we added spices to that? And cooking a ragu is a very similar process to cooking a chilli. It worked and it's now on the menu and we're doing a little dish of almost like a jacket potato with a strawberry chilli and some sour cream and some cheese. So it's very comforting and it's very familiar, but it's using ingredients and techniques in ways that are very unfamiliar and also allows us to use potatoes and strawberries, both of which are in season, both of which are sourced within 10 miles of the restaurant. So we're very happy to be able to showcase local produce in a really unexpected fashion.

Chris - So have you got anything I could cook that you think I am capable of knocking out?

Alex - I think that you should learn how to cook tempura vegetables. We are going to make a really super tasty, super simple tempura batter, which is something that people just don't do at home because they think it's challenging and they think it's something that they can only eat in a specialist restaurant. I'm not saying it's going to be in any way authentic, but it will be delicious. There's the fundamental lessons of making something delicious usually is, is it seasoned properly? And that means is it salted properly and does it have enough acidity? Because acidity is what keeps the palate alive and salt is what makes things taste delicious.

Chris - What do I do first?

Alex - We need to secure some seasonal vegetables, aubergine, broccoli, anything that steams well. Although it's being deep fried, the actual cooking process is done through a steam.

Chris - Right? I've written those down. We'll get James onto that in a minute. What do I do with them?

Alex - Wash them, peel them and then slice them into pieces that you think will cook within about two minutes or so when they're being fried.

Chris - So what a centimetre? Two centimetres?

Alex - Depending on the vegetable, you've got carrots, then I'd probably go with half a centimetre. But nice thin long slices because you want plenty of batter. So ratio is important here because you want the crunch of the batter but you also want the rigidity still in the vegetable, but it also has to be cooked.

Chris - It's the batter that's scaring me. The vegetables don't worry me, I cook them all the time, but the batter frightens me because I've never done this. So take me through it gently.

Alex - So essentially what you want to achieve in a tempura batter is lots and lots of air bubbles. To achieve that, we rely on a very simple chemical reaction between a base and an acid. We use a self raising flour, a gluten-free self raising flour, which already has some raising agents in it. To that we add a little bit extra bicarbonate of soda. We use soda water to make the batter, a touch of salt for seasoning. And then just before you batter the vegetables, I always add a touch of vinegar and I usually use white wine vinegar. And what the vinegar does is react with the bicarbonate of soda, creating lots and lots of delicious bubbles, which then activate in the fryer and give you a super light, super delicate batter on the veg. The first thing you see as the batter reacts with the hot oil, it will puff out and you'll get loads and loads of bubbles of carbon dioxide.

Chris - Well sitting here listening to all that is James Tytko from our team. Have you got all that, James?

James - Thanks Chris. Challenge accepted on the condition that I can solicit some help from someone I know will be able to offer some very well informed advice.

Alice - My name's Alice. I'm the manager of the Cambridge Food Hub and our purpose is to connect local producers in Cambridgeshire and its surrounding counties with businesses in Cambridge and primarily that's retailers but also cafes and coffee shops.

James - Thank you so much Alice. Down to business, we've got a task. Alex has set us an achievable recipe for a home cook. It's a version of the tempura dish they make at Vanderlyle. And the first ingredient on my shopping list is seasonal vegetables. And we're in the perfect place to acquire those at the Cambridge market in the middle of town. What should I be on the lookout for?

Alice - So you've picked a great time of year to use seasonal veg. This is like peak UK growing season, you've got calabrese like broccoli, it's local sweetcorn time of year as well, which is always exciting for people that grow that. French beans, loads of leafy green vegetables, spinach, lettuce, salad items. We're going to find this task okay, there's a lot of things growing at the moment.

James - So the mission is to make sure that as much of the food that ends up on the dinner plate is as good for the planet as possible. Is food miles the primary metric? I'm sure there are other factors as well, but is that the main one?

Alice - Food miles are important in that, like I said, we work with local farms, but I will say that in terms of judging the sustainability of a food product, particularly in terms of its embedded carbon, food miles are actually not so significant. Air freighting food is very bad for the environment, but shipping food is pretty low carbon, much more important is how food is produced. So, for example, if you get tomatoes that are grown in a heated greenhouse, so burnt fossil fuels to heat the greenhouse, even if they're grown locally, that's likely to be worse for the environment than if you've shipped tomatoes from somewhere where they are growing in season if it's a longer season, for example in Spain. But it's also about supporting the local food economy. It's about making sure that people feel connected to their food and also making sure that, as a country, we are resilient in being able to produce food for ourselves.

James - So, Alice, we've found a fruit and veg seller and he assures me that pretty much everything on the show here is locally produced and a whole lot of it's going to be seasonal as well, isn't it? We've got courgettes, broccoli, carrots, these are all the things you were mentioning. What looks good to you?

Alice - Yeah, I think I'd go for the courgettes, definitely. We've got courgettes coming out of our ears at the moment. There's so much of them being grown locally. Broccoli could be very nice. They've got a bunch of carrots here at the front.

James - Does freshness play a big part in taste?

Alice - Yeah, I think freshness is really important. The idea that we might pick up something from a farm on Monday and then somebody's eating it on Wednesday, so it's two days after it's been harvested vs if you've had to import something from another country, it's had to travel, it's likely to have had two weeks from it being harvested to it being eaten. But the impact that that has on taste really varies on what the food item is. So, for example, asparagus, a really classic seasonal product, you've got about six weeks where English or UK asparagus is in season and people know that is the time to eat asparagus. Outside of that you get it from Peru likely to have been air freighted because it's a fragile product. If it has taken a long time to get to your plate, then the sugars in this asparagus turn to starch and the taste of the product has changed. But, if you've got other vegetable items like peppers and aubergines, for example, classic Mediterranean vegetables, actually the taste can develop over time. But for a lot of things people who have their own gardens or allotments and grow their own food know that if you pick something and it's a perfect ripeness and it's perfectly fresh, it does taste amazing. But I do think when it comes to taste, what's really important is the variety of item that you are eating. So one variety of strawberry versus another. It isn't actually so much about where it's grown, that's just another thing to bear in mind. Some varieties are better quality and they do taste better and they've been bred for certain characteristics. And you can think about that when you're growing your own food at home as well.

A modern kitchen

18:10 - Vegetable tempura: putting the theory into culinary practice

Instructions and ingredients secured, it was time to don the apron...

Vegetable tempura: putting the theory into culinary practice

Ingredients acquired, instructions straight from the horse’s mouth - it’s time to see how Chris got on in the kitchen…

Chris - I've realised it is actually really hard to do cooking and chopping and hold a microphone. So I'm going to need some help here. Amelia kindly volunteered to help me. Should we have a look in the bag and see what James has got for us?

Amelia - So we've got one aubergine, one carrot and one courgette.

Chris - We've got some purple sprouting broccoli as well. I've got the recipe from Alex. So if I read you the things out, can you go and get the ingredients around the place? The first thing we need is self raising flour.

Amelia - Got some.

Chris - And we need some bicarbonate of soda. I did find some of that earlier. There's some over there. It's dated 2014, so I hope that still works. I bought the soda water, which is over there. We need a little bit of salt and we're going to need some white wine vinegar. Have we got any of that?

Amelia - Got some white wine vinegar.

Chris - Oh, we have actually. Okay. Can you weigh out a hundred grams of that self raising flour first?

Amelia - Okay.

Chris - Just a pinch of that bicarb and a bit of salt. You mix all that round now. Alex said do it dry first and then once we've got the dry coat on everything, once we've cut them up, then we make the mixture wet with the soda water and the vinegar and that then makes it froth a little bit and makes the batter all light. I'll peel the carrot so I can probably manage that. Do you want to chop up the courgette and the aubergine and the broccoli? And I'll go and peel this carrot. Mind your fingers. We don't want any tempura finger.

Amelia - Not vegetarian.

Chris - Okay, I'm going to put the batter mix in this bowl. So I reckon they're all nice and damp, so they should go in there and get coated. He said put them in dry first, Then we make them wet.

Amelia - Courgette first.

Chris - We are getting courgettes now that are basically disks covered in the flour and the bicarb mix. They have coated pretty well actually, haven't they? I was expecting them to go a bit more lumpy, but it's gone okay. So we now have broccoli that looks like Christmas trees covered in snow. Okay, right, got the broccoli. I'll leave you to do the aubergine and the carrots. I'm going to go and sort out the oil. Let's light the gas. The oil is heating up. I will go and get the soda water and the vinegar. I've got measuring jugs.

Amelia - What does the soda water actually do?

Chris - According to Alex, because it's full of carbon dioxide, that's what makes it fizzy and it's a bit acidic. And we're going to add some vinegar that's also acidic in a second. This reacts with the raising agent in the self raising flour and the bicarbonate of soda. And it releases even more CO2. And that makes the batter we've made much more fluffy and bubbly, crispy.

Chris - It's fizzling. Kind of like pancake mix sort of. Now I need to add a dash of vinegar to that. Oh, it's fizzing. That's really fizzing now. Right now what we need to do is put your bits of vegetable through that mixture and then drop them in. Should we do one of each first just to see what they look like.

Amelia - One bit of broccoli.

Chris - Broccoli's in the wet mix.

Amelia - Quite thick, but light at the same time.

Chris - Drop it in. Let's see what happens. He said two minutes and it'll go a sort of brownie crispy colour. Good. What we're doing now, carrot. Looking good. That is looking good. And you can see where the batter is frothy. It is all kind of fluffy but crispy. It's amazing. And the carrot - that looks good.

Amelia - Gorgeous as well. It's cooking fast.

Chris - It is cooking fast. Here's a plate.

Chris - Can we do more broccoli? That looks so delicious. I'm dying to have that. We've got the things we cook first now out on the plate.

Chris - I've already had dinner and I'm feeling hungry. We need to dip it with some sweet chilli. So let's just get that it's in here. Are you ready? I'm ready.

Amelia - Really good.

Chris - The batter is beautiful.

Amelia - It tastes just like prawns as well.

Amelia - Delicious. That's a lot better than I thought it was going to be.

Chris - I've enjoyed making it. It didn't take us very long to make it. Really, really tasty.

Amelia - Quick 15 minute meal and you're sorted.

Chris - Would you do it again?

Amelia - Absolutely.


24:34 - The multi sensory experience of eating

Could weighted cutlery affect our flavour expectations?

The multi sensory experience of eating
Charles Spence, University of Oxford

To provide some final thoughts on what they’d heard, Chris Smith asked experimental psychologist, and food and drink guru, Charles Spence whether who was cooking might make a difference to how food tastes…

Charles - I think we can think of the star chef as a kind of brand and, generally, if we like the brand things taste better as a result. I think we very often taste what we expect to taste as much as actually what we have in our mouth. We make a prediction about what food is going to taste like. So, if it comes from a star chef, we think it's going to be great. And then when we put the food in our mouth, we check it to see if it's what we expected. And if it is, then we live in the world of our flavour expectations as much as in the world of our experience itself. But of course it's not just the chefs who might boost our perception of the taste of the food, the fact that you were making the tempura yourselves probably also has a role to play. And there's research out there showing that if you give people partly prepared meals to finish off in their own kitchen and then you give them a dish that you say, well, you finish that dish off yourself, you are part of the process of cooking versus somebody else. If your colleague made it then we all think that the food that we had a hand in making tastes better than that was made by somebody else, even if it's identical food. It's kind of like the Ikea effect in the kitchen.

Chris - Someone did say to me that even the weight of the cutlery and the chink of the glasses, that also affects our perception of how good or how high quality a food stuff is.

Charles - Absolutely. So the first thing I do when I go to a restaurant is to pick up the cutlery, the knife and the fork, and give it a little balance in my hand, see how heavy it is. We've done a number of studies now both in the laboratory but also in fancy five star hotel restaurants where we take large groups of people and on half the tables we put the heaviest cutlery we can find, and for the other half the tables we just put the light, canteen cutlery instead and serve people exactly the same food in exactly the same place on exactly the same day. When we ask them to rate how much they like the food, how much they'd be willing to pay for it, a dish like that in a place like they find themselves in, time and again we find that the heavier the cutlery the better people rate the food and the more they're willing to pay for it. So one of the simplest ways perhaps to improve the taste of your food.

Chris - Was Alex's advice to cook tempura particularly sage in the sense that he made me eat something crunchy because I also read somewhere that we've evolved to like crunchy stuff because our brain says fresh if it's crunchy.

Charles - Absolutely. I was listening to the sound of the crunch and thought it sounded very tasty. And indeed, most of the things we like, especially the snack foods, tend to be noisy. They're crispy, crunchy, crackly, even creamy and carbonated food makes a sound. Our brains seem to like that. And whether that's because it signals freshness in fresh produce or perhaps fat content in baked and fried goods, we're not quite sure yet, but certainly it is a very appealing sensation even though it doesn't directly contribute to any nutrients or anything we need in our diet. Nevertheless, we like that sonic reassurance, I suppose, that what we're eating is perhaps fresh.


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