Matthew Kenney places before me a vibrant plate of green dumplings, drizzled with a red juice. “The kimchi dumpling,” he says with a flourish as he takes a seat under an olive tree in the garden of his flagship Los Angeles restaurant Plant Food and Wine. “It’s a dish I created six years ago: red cabbage kimchi with sesame, cashew and ginger, wrapped in young coconut with cilantro and spinach, which is pureed and spread thin and dehydrated. Then it’s topped with a sesame-milk foam.”I have a bite — it is sensational. I am not vegetarian or vegan or plant-based. (Plant-based takes vegan one stage farther, eliminating all processed food.) Before taking on this assignment I did not know my kombucha from my kimchi. If I thought about plant-based food at all I would have assumed that it meant eating a lot of kale and blueberries. The dish before me makes me think again. If plants can be woven into food that tastes this good, then I for one would like more of it.

Kenney, the world’s leading plant-based chef, has just opened a new restaurant in London, Essence Cuisine in Shoreditch, serving a multitude of imaginative dishes including his signature heirloom tomato lasagne (layers of courgette and tomato topped with sundried tomato marinara, pistachio basil pesto and macadamia ricotta). It is part of a wave of American plant-based cuisine coming to London. The more casual By Chloe, which is a hit in New York with five outlets, is also opening in Covent Garden this autumn, serving its trademark guac burgers. London, reckons Kenney, is ready. “It’s reaching a tipping point. The intelligence and awareness are there. In a blink there will be a new food landscape.”

Meat, claims Kenney, will soon be as socially unacceptable in restaurants as smoking. “It will become the new cigarette — where it’s just not cool to consume it, at least not factory-produced meat. It may sound hard to imagine, but 20 years ago it would have been hard to imagine no smoking in restaurants. It may not become illegal to eat the way we eat now, but it will certainly be passé.”

With his culinary schools and an online cooking academy, Kenney trains plant-based chefs from all over the world. “Fast, casual places like Pret understand what is happening,” says Kenney, who is sipping a kombucha (a probiotic tea). “They sent one of their top chefs to our school.” Last year Pret a Manger opened a meat-free version of its chain, Veggie Pret, in London. It was an experiment, but it proved so successful that it soon opened another and is planning more.

It helps that Kenney is a living advertisement for the plant-based way of life. Aged 53, he could easily pass for being in his mid-thirties. Slim with dark hair and an unlined face, he says he still “gets carded” once in a while — meaning that he is asked for his ID when buying wine. “I don’t think they think that I’m 21, but they probably don’t think I’m so far over.”

In a blink there will be a new food landscape Matthew Kenney

Which brings us to wine. Perhaps surprisingly, Kenney is a huge advocate of wine and champagne and says that he drinks a couple of glasses most days. “It makes me happier,” he says simply. “I love the taste and the aroma and I think it really brings out the flavours in this food.” At Plant Food and Wine they have a “champagne campaign” — half-price bottles offered with weekend brunch.

That is key to what is going on here. Nothing about Kenney’s restaurants suggests an ascetic lifestyle. The food and the environment are hugely attractive. Every plate is beautifully presented and Instagram-worthy — but the diners are not just young and hip. On the day I visit a family of three generations is at one table, a trio of middle-aged men at another.

Big money is behind the movement away from a traditional meat diet. Last month Richard Branson and Bill Gates invested millions of dollars in a start-up, Memphis Meats, that grows “clean meat”, ie grown in a lab from animal cells. Then there is Kenney’s business partner, Prince Khaled Bin Alwaleed, the 38-year-old Saudi billionaire whose outspoken views — and sizeable wallet — have done much to revolutionise the food industry.

“People who opt for plant-based lifestyles have the right to demand better-quality options with diverse cuisine — not just expect a menu with three side-salad options,” says Prince Khaled when he contacts me from his travels in Europe.

“Matthew is introducing cuisine that is exceptionally appealing and aesthetically masterful.” Prince Khaled used to live a life of lavish excess, including exotic trophy hunting trips and meat-heavy gourmet meals. I ask what prompted him to change. “I didn’t feel right about my life,” he replies. “It went against what I felt was good and just, and I was truly unhealthy and out of shape . . . I even gave up my car due to the leather seats.”

Kenney had a similar awakening. Growing up in Maine, where his father ran a construction business, he used to hunt deer as a child. His parents still have the head of the first buck he shot on the wall of their home in Maine. When he was aged 15, one of his friends made a derisive comment about his weight. He instantly stopped eating junk food and started frequenting the organic hippie co-op in a nearby town. “I started taking my own healthy food to school. I would make wholewheat pasta with tomato sauce or brown rice with a bunch of herbs and vegetables. Just simple stuff, nothing that we serve on our menus today.”

After training as a chef in New York, he opened his own restaurant, Matthew’s, in 1993 and was named Food and Wine Magazine’s best new chef the next year. Focusing on Mediterranean cuisine and quality ingredients, the format was nonetheless traditional. “There were ten entrées and not one was vegetarian. Every now and then somebody would come in and ask for a vegetarian dish. In ten years I don’t remember anybody asking for a vegan dish.”

It wasn’t until 2003 that he decided to open a plant-based restaurant after a friend “forced” him to visit one in New York with Sarma Melngailis, his girlfriend at the time, who was once nicknamed the queen of vegan cuisine. “It was weird,” says Kenney. “I let my friend order for me and I actually didn’t love my experience, but I thought that the logic behind it made sense. The place was small, but full of these super-healthy-looking people. And I felt great after the meal. I thought, ‘Wow, if somebody can make this food taste better it’s going to be huge.’ ”

People realise that healthy eating does not have to be a dragSamantha Wasser

So he and Melngailis created their own vegan restaurant, Pure Food and Wine, which opened in New York in 2004 and was an instant success, with regulars such as Alec Baldwin and Bill Clinton. However, their relationship soon foundered and Melngailis bought out Kenney’s stake. She is now in jail, serving time for grand larceny and fraud. It is a long and complex story; suffice it to say that her new nickname is “the vegan Bernie Madoff”. Kenney shakes his head: “It doesn’t make any sense to me. It’s not how I knew her.”

Kenney is no stranger to legal woes himself, with lawsuits often trailing him across the country. In his autobiography, Cooked Raw, he goes so far as to quote someone who once said that his story has “all the makings of a Hollywood movie: good looks, bad relationships, heartbreak and deceit. And lawsuits, lots of lawsuits.” When I quote it back to him, he nods: “You can’t hide from that stuff. You have to own your mistakes. I tend to be too optimistic and get into projects that are maybe too ambitious.”

After splitting with Melngailis he moved to Los Angeles, where he found an even more receptive audience for his innovative cuisine. He now has three restaurants there, all slightly different in style, but all plant-based and hugely popular. He lives in Venice with his 22-year-old vegan girlfriend Charlotte and (non-vegan) cat Rumple. “She [the cat] eats raw organic poultry.” Does it bother him? “It doesn’t really,” he says nonchalantly.

Although Kenney practices yoga and meditation, he says the stress of the business sometimes gets to him. “I’ve been tired or upset or angry, but I’ve never considered giving up.”

Kenney’s mission is to make plant-based cuisine as widely available as possible. He is convinced that once people try it there is no looking back. He cites places all over the world, including in South America, that have successful plant-based restaurants and is opening one himself in Bogotá, Colombia, in November. Earlier this year, with the backing of Prince Khaled, he also opened the Plant Cafe in Bahrain, and they are planning several more in the region.

Samantha Wasser, the 30-year-old co-founder of By Chloe and creative director of ESquared Hospitality, the company that owns the brand, agrees that if you build it they will come. “We are seeing an outcry for plant-based eating in smaller areas because they are under-served. People have realised that healthy eating no longer has to be a drag,” she tells me when I call her in New York. “Probably only about 10 per cent of our customers are full-time vegan. I think that shows how much of a demand there is. A lot of people just want to be incorporating it, whether it’s once a month or every day.”

“It’s a complete shift in the way we eat,” says Kenney, pointing out that hospitals and even schools in America are offering plant-based menus (the Muse School in Los Angeles is exclusively plant-based). Sportsmen such as Tom Brady, who focus on plant-based foods, have helped to change the image of such a diet. Even Arnold Schwarzenegger has jumped on board. “It’s all about education and awareness,” says Kenney.

He has a point. After my crash course in plant-based eating, I no longer breeze past the kombucha aisle in my local Whole Foods (yes there’s a whole section dedicated to it). I even found myself returning to Plant Food and Wine at the weekend — voluntarily. And it wasn’t for the half-priced champagne. Well, not just for that.

Veganism, the posh way: Matthew Kenney’s hearts of palm ceviche

Serves 6
Ingredients
60ml lime juice, strained
60ml orange juice, strained
1 tbsp jalapeño pepper, seeded and finely diced
1 tbsp Fresno chilli pepper, seeded and finely diced
1 kaffir lime leaf, sliced very thinly
60ml olive oil
450g hearts of palm
Garnishes (see method)

Method
1 Whisk the citrus juices, jalapeño, Fresno chilli, lime leaf, olive oil and ½ tsp salt in a bowl. Add the hearts of palm, making sure they are completely covered with brine. Cover bowl and refrigerate for at least 30 min; overnight is preferred.
2 Spoon some of the ceviche brine on to the plate. Place the hearts of palm on the brine. Top with fruit and vegetables of your choice. We recommend avocado, radishes, kumquats, citrus segments and quartered cherry tomatoes. Garnish with microgreens, oils (orange, lemon and pine), edible flowers and/or sprouts of your choice.