The writer and bon viveur Michael Winner is used to getting his own way. When he doesn’t, he can be quite sensationally rude, using his restaurant review column in The Sunday Times to vent his fury in print.

Thus did Rachel Lewis, the manager of The Petersham Café, incur a sustained attack, over several weeks, after she told Mr Winner that, with regret, she was unable to accommodate his party of eight for Sunday lunch. Ms Lewis was “the rudest restaurant manager” the silver-haired titan had ever come across in his life and should be sacked. At the same time, he praised the cooking at Petersham as “superb”, singling out a chickpea, sweet potato and spinach curry as “memorably excellent” and a ginger pudding as “historic”.

The object of his praise is Skye Gyngell, the tall, blonde fortysomething Australian chef whose cooking has been attracting similar attention since she started sending out flavoursome and exquisitely presented lunches from a potting shed in the pastoral enclave of Petersham Nurseries, down river from Richmond in southwest London.

I am here for lunch just after the latest volley of abuse from Winner and the staff are still smarting: “Rachel is the loveliest person,” exclaims Gyngell. “You just wouldn’t recognise her from his description.” The restaurant is booked out at weekends over a month ahead: “We only have a set number of tables,” says Gyngell, whose kitchen has now moved to slightly larger premises — a garage that used to house her employer’s Ferrari.

“To accommodate Michael Winner’s party we would have had to ring people and chuck them off; I’m not prepared to do that. He was offered a table for two but that wasn’t acceptable: he doesn’t get the ethos of the place.”

With unusual candour, Gyngell admits that her friend and mentor Rose Gray, of the River Café, rang her up after the Winner incident and suggested, gently, that she needed to grow up. “She said we had to learn to play the game: that you must always be able to fit certain people in; it’s part of business.”

So will she in future? She scowls: “Maybe, but that man’s not bloody well coming back.”

Oh, I do love a plain-speaking Australian. She sits opposite me among the ferns and climbers and the tasteful, thrown-together look of the glass-covered café, with her apron still on and shiny skin from a long, warm session in the kitchen. She was there in the hatchway when we arrived for lunch, blonde hair scraped back, finishing dishes before they went out, calling instructions to staff.

Our meal was gorgeous: fig, prosciutto and dolcelatte on a small, colourful hillock of summer leaves; scallops with a dusting of crisp sourdough crumbs and, for my tall, hungry son, a piece of well-hung beef with summer vegetables. I couldn’t remember the last time I’d enjoyed a meal so much — probably at someone’s house, rather than a restaurant. Gyngell has that knack of providing homely comforts that is characteristic of women chefs such as Alice Waters, Sally Clarke and the Australian Stephanie Alexander. Though like any perfectionist chef, her warm, den-mother approach to staff relations can fray a little when things hot up in the kitchen: “We are shouty people,” she says, “There’s a lot of ‘What the f . . . ?!’ The nursery staff think we are noisy and a bit rude and I think they are slow and pottery.”

There are those who predict a meteoric career for this talented cook, who is Vogue’s food editor as well as a favourite with an A-list clientèle — Mario Testino, Madonna, Charles Saatchi — from the days when she cooked for private dinner parties. It was she who was supposed to have been supplying recipes to Nigella Lawson for cash in the Nigellagate furore (she says she was paid to test the recipes, not to supply them) and she has an influential following.

Petersham was voted Best Al Fresco restaurant by Time Out and won Tatler’s Most Original award this year. But Gyngell says she’s not excited by fashion and fame; only by food. “I’m not interested in running a West End-style place that people just want to be seen at. I’m going to be honest: the food at The Wolseley, for example, is just unapologetically awful, but people don’t care; they just go there because it’s fashionable. I like conviviality, dogs, children. It’s about sharing, breaking bread, taking time. Cooking is a craft which deserves patience and consideration.”

And it is cooking that has made Gyngell happy. She grew up in Sydney, daughter of the TV mogul Bruce Gyngell — whom she describes as a “typical marauding Australian workaholic who had thousands of affairs and huge enthusiasms” — and a “beautiful, stylish, artistic mother”. Skye herself was gawky and freckled, and found it difficult to live up to her parents.

At 17 she started using heroin — the beginning of a 20-year addiction during which she started and abandoned a law degree and then worked her way through a kitchen apprenticeship that took her from porter in a Double Bay deli in Sydney to La Varenne cooking school in Paris in 1981, The Dorchester, The Sugar Club and eight years as a private chef. She married, had a daughter, now 16, and divorced. She has an eight-year-old daughter with her current partner, James Henderson.They are happy now but, at one low point in her wilderness years, he locked her out of their home.