Miguel Barclay is due to serve me dishes from his new cookbook, One Pound Meals, based on the Instagram and YouTube videos he’s been posting online for only nine months, at his Camden flat, which has one bedroom and two kitchens. However, his wife Lucy is ill so he comes to my house instead, bearing ingredients, condiments and pans in a rucksack, having set up a webcam so he can check in on her. “Raise your hand if you’re OK,” he shouts into his phone, and a shaky hand rises from a pile of bedding on the screen. In a profession full of oddballs, Barclay may be the most unusual cook I have met.

Before he settles down to prepare crab mac and cheese and peppers stuffed with couscous, spring onion and feta, the bearded, cheerful 36-year-old leafs through his cookbook with me. “Look at this: smoked mackerel fishcake, quiche lorraine, both well under a quid. This chicken tikka masala tastes as good as one from a takeaway and it costs 80p. Aubergine dahl and flatbread — that costs about 30p, it’s crazy.”

He pauses at a chicken ballotine with potatoes that looks in the photo like something from Le Gavroche. “That’s a bit more of a show-off dish; it takes a bit more time,” he says. Ideally, the recipes in the book should take 20 minutes to prepare from scratch. And, as it says on the cover, the ingredients for a single serving — everything apart from salt, pepper and oil — should cost £1 or less.

I had assumed that Barclay came up with the idea for One Pound Meals out of necessity or at the very least that he was surfing the zeitgeist of austerity. It turns out that neither is true. He is a trained biochemist who gave up a lucrative career designing websites and apps for ecommerce sites to devote himself to his hobby of cooking and specifically to the creation of simple recipes. He adopted the £1 price point only as a way of keeping it interesting. He put his experiments on Instagram to get feedback rather than to help struggling families or underpaid singletons in bedsits to make ends meet.

“Everyone wants me to be preaching something but I’m not,” he says. “There’s no hidden agenda. There’s no message. I just like really simple food. Most of the dishes I was doing [for myself] were two or three quid, so I thought, ‘If I can do it that cheap, why don’t I aim for a quid?’ That’s pretty cool. I like to challenge myself and come up with problems I can solve. Some people enjoy sudoku to get their blood flowing. For me it’s either creating a dish for under a quid or taking an existing dish and reworking it so it costs less than a quid.”

Calculating the cost of the ingredients in a single serving, rather than the total amount he has to buy, “is the only way it works”. The stuffed pepper he is making me is part of an 89p pack of three, so he calculates the cost at 29.6p, plus the tiny fraction of couscous he uses from an 89p kilo bag, and whatever a single spring onion and a sliver of feta cost. All the recipes are for one person, so if you are cooking for a family of four, it doesn’t matter if a recipe calls for, say, a quarter of a cauliflower.

And even if you are cooking alone, he works from a basic list of ingredients — chicken thighs, mince, cheddar cheese, potatoes, aubergines — that can be used across many recipes. Mostly he keeps to core foodstuffs that supermarkets price keenly to attract repeat custom. Early on he shopped in Lidl and Aldi but says that sometimes Sainsbury’s will be cheaper for courgettes, or Morrisons for cauliflower. Sometimes he checks prices online, sometimes in person, keeping notes in a spreadsheet.

Actually, he says, simplicity is more important in his dishes now than price, and shopping in supermarkets is part of that. His Instagram videos always showed his hands rather than his face so that the viewer could imagine themselves making the dish: “Also, I’m quite shy actually. But now people want to know who the £1 man is.” When the videos began to gain traction (he has 134,000 followers) he was invited to make his chicken katsu on This Morning for Eamonn Holmes and Ruth Langsford and made breadcrumbs for it with a stale loaf and a cheese grater because he reckoned using a food processor would seem like too much of a faff to most viewers.

Some people enjoy sudoku. For me it’s creating a dish under a quid

There are beneficial side-effects to his intellectual gastronomic experiment. “A bought bolognese sauce by [he names a famous brand] will have four tablespoons of salt, four tablespoons of sugar and stabilisers in it and it will cost £4,” he says, “but for a quid you can make everything from scratch and it still takes 20 minutes and you are using actual tomatoes that haven’t gone through a preparation. So there are health benefits to it.”

Barclay’s recipes have come to the attention of the campaigner and food writer Jack Monroe, who started a frugal food blog while a single parent on benefits. “My mum alerted me to Miguel, and his stuff is just so gorgeous and accessible and funny,” she tells me. “People often ask me if there’s any rivalry — of course not! I think there’s room enough for all of us. I started out by admiring Frugal Queen, Ms Marmite Lover and Thrifty Lesley and they all embraced me as a budget-cooking friend rather than competition, and we direct readers to each others’ blogs and share recipes and keep in touch. I love seeing what other people come up with, and the reality is that so many people struggle to make ends meet, so the more of us there are offering a guiding hand in the kitchen the better.”

The mac and cheese and the peppers are ready and prove to be as delicious to eat as they were quick and easy to prepare. Barclay came up with the idea of tinned crab for the former as a cheap alternative to lobster. He spent days making paella over and over, desperate to re-create the golden hue without using exorbitantly priced saffron, eventually managing it with a pinch of turmeric and oil from fried chorizo. His chicken panzanella tray bake went through four iterations. He created a goat’s cheese wellington as an alternative to beef wellington and is still working on a slow-roast ragu di manzo that stubbornly refuses to come in below £1.

Barclay was born in Surrey to an English father and a mother from Seville, both of whom work for the NHS. The family wasn’t particularly foodie, but ate meals together and enjoyed Spanish and Italian cuisine. He spent every school holiday — and, later, his breaks while studying biochemistry at the University of East Anglia — washing dishes in restaurants. He never aspired to cook in kitchens, he says, but loved watching chefs: “It was like watching a documentary about a kitchen in real time every day.” At university, around the time when Jamie Oliver turned a new generation on to food, he started cooking for fun.

After graduating, he got a job sequencing DNA for pharmaceutical companies in an outsourcing lab in Cambridge, but chucked it in. “I was only earning, like, twelve grand, and I wanted to move to London,” he says, “so I came down and started designing websites.” Did you do a course, I ask. “No,” he says insouciantly, “I taught myself.” These were the early days of ecommerce, when there were fortunes to be made. He bought his flat and last year began slowly scaling back his online work to devote himself to cooking, teaching himself to edit and post videos online as he went.

Lucy, whom he met at university and married four years ago, is the events organiser for the RAF Museum at Colindale; she agreed to cover the household expenses for a bit while he devoted himself to his hobby. She didn’t object when he turned their second bedroom into a second, more photogenic, kitchen, doing all the plumbing and wiring and carpentry himself. “Because of the way my mind works I just love learning new stuff,” he says. Slightly in jest, I ask if he has ever been tested for obsessive-compulsive disorder. “I think OCD is my superpower,” he says, laughing. He didn’t set out to be famous or successful and thinks he was lucky to happen upon the £1-meal concept, which caught on and was easily hashtag-able.

Publishing a cookbook was a fantasy of his (he owns about three hundred, but mostly just looks at the pictures). Immediately after his This Morning appearance four publishers approached him. He won’t say how much his advance was, “but I am pretty sure I broke the record for a non-televised debut cookbook”. He put the book together with a photographer in three months — conception, execution, everything — and says he has already come up with 100 recipes for the next. If people only cook about six dishes from most cookbooks, he wants them to cook “at least ten times that” from his. “These recipes speak to everybody, not just a certain demographic,” he says.

They certainly speak to me. Despite ribbing Barclay about his possible OCD I am pathologically aware of the price of the food I cook. I’m not mean, and will happily fork out large sums for good fish or meat but I also recently opted for canned rather than frozen broad beans for a soup because a) they were 50p cheaper and b) most of the frozen ones would go to waste. My wife and I made a fairly pricey stew for a dinner party on Saturday, but then eked it out, adding leftover vegetables, for two more days. However expensive, it’s good to know the value as well as the price of what we eat.

Barclay leaves me half a tin of flaked crab when he leaves to tend to his poorly wife, and the next day I use two free-range eggs (50p) and a bag of spinach (£1) to make it into an omelette. Not quite a £1 meal, but close.

Eight recipes for true tightwads

Balsamic sausage casserole — 96p per serving

To make 1 portion
Ingredients
2 sausages
Half a red onion, sliced
Half a yellow pepper, sliced
1 tsp plain flour
200g chopped tomatoes (from a 400g tin)
1 beef stock cube
1 tbsp balsamic vinegar
Olive oil
Salt and pepper

Method
Grab a casserole dish or a saucepan and fry the sausages in a splash of oil over a medium heat until cooked through and nicely browned on the outside. Remove the sausages from the pan, cut them into chunks, then return them to the pan along with the onion, yellow pepper and a splash of olive oil. Season well and fry for a few minutes until the onions are soft and starting to colour. Add the flour and stir for 30 seconds, then add the chopped tomatoes, crumble in the stock cube and add the balsamic vinegar and just enough water to cover the ingredients. Simmer for about 15 min, stirring occasionally, until the sauce is nice and thick, then remove from the heat and serve.

Chicken panzanella tray bake — £1

To make 1 portion
Ingredients
2 chicken drumsticks
A few small tomatoes
Quarter of a yellow pepper, roughly chopped
Half a red onion, roughly chopped
1 tbsp balsamic vinegar
Chunks of stale bread
Olive oil
Salt and pepper

Method
Preheat your oven to 190C/gas 5. To make the finished dish look extra lovely on the plate, deeply score the drumsticks to the bone in the middle and at the narrow end. Season with salt and pepper and drizzle with olive oil, then roast in the oven on a baking tray for about 15 minutes.

Remove the tray from the oven and add the tomatoes, pepper and onion. Season well and drizzle with more olive oil and the balsamic vinegar. Cook in the oven for a further 25 min, throwing in the bread about halfway through, until the chicken is golden brown and cooked through.

Mop up all the juices with the toasted bread and enjoy your tangy oven-roasted chicken panzanella salad.

Crab mac and cheese — 97p

To make 1 portion
Ingredients
100g macaroni
Half an onion, finely diced
1 garlic clove, sliced
Pinch of dried chilli flakes
Squirt of English mustard
1 tsp butter
1 tsp plain flour
100ml milk
Handful of mature cheddar, grated
1 tbsp crab (tinned)
Olive oil
Salt and pepper

Method
Preheat your oven to 190C/gas 5. Bring a pot of salted water to the boil and cook the macaroni al dente. Meanwhile, in a saucepan, gently fry the onion over a medium heat in a splash of olive oil. After a few minutes, when it starts to go translucent, add the chopped garlic and continue to fry until the garlic starts to brown. Then add the dried chilli flakes and a squirt of mustard, stir and then add the butter. As soon as the butter melts, add the flour and stir until the flour has disappeared. At this point add the milk very slowly, bit by bit, while continuing to stir. Once you have a thick sauce, remove from the heat and stir in the cheese. Taste and season if required. Next, add the crab and macaroni to the sauce, stir and transfer to a lightly greased oven-proof dish. Cook for 30 min and enjoy on a cold winter day.