MANY know Marcus Wareing best for his measured, often tough, critique on MasterChef: The Professionals, delivered with those steely blue eyes and leaving experienced chefs wishing they’d never dared serve the acclaimed restaurateur a panna cotta without the correct amount of wobble.

The 49-year-old has spent five years on the BBC show, an appointment he says has been his career highlight, with Gregg Wallace and Monica Galetti.

Wareing now splits his time between his main home in Wimbledon and a country house in East Sussex with a kitchen garden, where his three children Jake, 18, Archie, 15, Jessie, 12, congregate at weekends.

He has just released his seventh book, runs three restaurants (his flagship at The Berkeley has one Michelin star, after losing its second earlier this year) and he’s fired up.

“I cannot believe the amount of plastic waste we throw away as a family because of supermarkets. It’s insane. It drives me crazy. We have a massive, massive issue here and it really needs stopping and stamping out,” he declares. “Don’t get me going on plastic.”

He finds kitchen food waste just as intolerable and there’s as little as possible of it in the Wareing household, an issue he’s tackling in his new cookbook, Marcus Everyday.

“I hate waste. My father is a fruit and potato merchant, we never threw anything away,” he says. “As a chef, you’re taught to look at produce, to nurture it, to store it well, and you don’t throw things away. That’s been ingrained in me.”

He and his wife Jane talk all the time about how best to avoid waste and what they can use up at home. “We don’t have money to waste,” says the chef. “I don’t, that’s for sure. And I’m certain a lot of people out there in the world don’t.”

It’s not always easy though, to be a savvy shopper and organised enough to use absolutely everything in the fridge before there’s a tinge of green, as many of us know. “We’re not perfect,” he concedes. “We still have to work at it.”

His new recipes for less food waste include Tuscan-style panzanella, frittata with piquant fruit chutney and sticky banana pudding with rosemary. Even past-its-best milk doesn’t need to be chucked. That’s right, you can turn it into homemade ricotta (with a radicchio, orange and dill salad). “It’s not dangerous,” Wareing assures. “It’s simple and straightforward.”

He knows it is easy for him to say that as a chef but adds: “I want to reflect on the importance of what we purchase when we go out shopping.

“Don’t shop on your way home from work, don’t shop when you’re hungry, because you buy more food than you need. Look in your fridge before you go, write down what you’ve got. Preserve things, freeze things. If you just do a good shop once a week or once a fortnight, and you’ve bought things with a bit of thought, you’ll always find something to eat.”

The new book is made up of chapters that might surprise, one going against the recipe book grain for dishes for two, four or six plus people, and aimed squarely at those cooking only for themselves – like the croque monsieur with homemade bechamel, or butter-roasted cauliflower with capers and parsley.

Wareing is no stranger to cooking for one, particularly during the earlier years after long kitchen shifts (he worked under Gordon Ramsay at Aubergine). “I was either at work or came home and no one was there,” he says.

The book also has recipes conjured up from what he grows in his Sussex garden – think crispy courgettes with goat’s cheese and lavender honey or roasted Jerusalem artichokes with prunes, lentils and sour cream.

“When you pick things you grow yourself, it’s quite extraordinary, it’s a level of freshness that no shop or supermarket can give you,” he says.

l Marcus Everyday is published by HarperCollins, priced £20. Available now.