The gospel according to Gordon Ramsey (Warning: it may be enough to put you off your breakfast)

Argumentative, brash and confrontational, Gordon Ramsay is as well known for his bad temper and four-letter outbursts as for his unquestionable culinary flair. Now the Glasgow-born chef has picked a new target for his rage: the Big Mac.

In a rare interview, he also offered a tantalising insight into the drive and ferocious temper that have propelled him from chopping vegetables in pub kitchens to a multimillion-pound international empire.

First, a few scores need to be settled. Ramsay-watchers will not be surprised to learn that there is history behind his latest outburst. In his attack on junk food he rekindles his war with mentor-turned-nemesis Marco Pierre White.

Earlier this week, White horrified the world of haute cuisine by claiming that the secret of his success was the Knorr chicken stock cube. But it was his recent comments about the fast-food chain McDonald's that really enraged his fiery former pupil.

"From a chef's point of view, Marco is talking absolute, utter crap," says Ramsay, during an exclusive interview with The Independent on Sunday in the kitchen of his eponymous west London restaurant.

White claimed that McDonald's offered better food than many of London's top restaurants - several of which are owned by Ramsay. He praised the US chain's consistency, saying: "You have to look at whether restaurants offer value for money, and they offer excellent value ... I am not saying you should live off them, but there is a time and a place for McDonald's."

Needless to say it is a sentiment that Ramsay, the proud winner of 10 Michelin stars, does not share. "Did you see what happened to that guy who ate fast food for 30 days in the Super Size Me documentary?" he asks incredulously. "To turn around after that and say that McDonald's is consistent: it is consistently bland.

"Strip a Big Mac back of everything it's filled up with and you've got two bland basics: fat and fodder. When you think of how exciting it is to make a hamburger from a chef's point of view - with ground mince, ketchup, Tabasco and onions - and how easy that is, then why do you have to buy that crap? When you've got children, you have to scare them - to make them understand that this kind of thing is not good for you," says the father of four. "We're 20 years too late for this shit in terms of banning junk food."

Ramsay, who decided to pursue cookery after a promising football career with Glasgow Rangers ended through injury, started out in White's kitchen at Harvey's at the age of 19, before going on to study under other celebrated names in both Britain and France. He finally won a Michelin star of his own for Aubergine at the age of 28, shortly before marrying his wife Tana. Now splitting his time between business interests in Britain, France and the US, Ramsay is worth a reported £60m.

Controversy wafts behind him like kitchen smells. Yesterday it was reported that his latest venture, The Narrow, in Limehouse, east London, features no fewer than a third of the dishes in a cookbook by one of his rivals. Critics suggest British Regional Food, by Mark Hix, whose company Caprice Holdings is behind The Ivy, Le Caprice and J Sheekey, features too prominently at The Narrow. Ramsay denies stealing any recipes and says he and Hix are friends.

Last week, he was in a belligerent mood as he prepared to film a TV commercial for BT Business. The mere mention of business is enough to send him into another White-inspired rant: this time about why his former boss's businesses faltered. "Chefs are shit at running businesses," says Ramsay. "When you look at the fuck-ups with Marco and [Jean-Christophe] Novelli, and what they've done in terms of how their businesses have disappeared and sunk without a trace, it's because they've tried to run those businesses themselves."

Ramsay gladly leaves the business side of his multimillion-pound empire to his partner and father-in-law Chris Hutcheson. "Chefs are just shit at things like IT," says Ramsay. "Employ somebody to do it for you. Play on your strengths, and improve your weaknesses."

Playing to his strengths is not always a guarantee of success. Ramsay's latest major business venture, a New York restaurant called Gordon Ramsay at The London, had a rocky start. Though it is booked up many months in advance, the critics have not all warmed to it. In particular, The New York Times's food writer Frank Bruni got Ramsay's back up by giving the restaurant two stars out of four and then criticised all manner of other things on his blog.

"The fat, lazy thing about Frank Bruni was all the little seedy, undercover blog bullshit," says Ramsay. "I don't give two fucks about it. Never have; never met the guy; not even remotely interested. I'm being judged on my persona as opposed to my food, and you know what? Fuck it.

"The thing I find fascinating is, what qualifications do you need to become a food critic then? None. Good luck to them. You look at Giles Coren who's got an advert for Birds Eye fish fingers, and he's the food critic of The Times and it's like 'hello'? A A Gill writes cookbooks for The Ivy and Le Caprice, takes a nice advance from them, and then comes to pan others. You know, fuck all that shit."

What is your secret ingredient? Six chefs open up their stock cupboard

Clarissa Dickson-Wright:

Heinz tomato soup

"There's a place for the stock cube in every kitchen, but I prefer my own stock"

Richard Corrigan:

Organic Swiss vegetable bouillon

"I only use it at home, not in the restaurant. A stock cube would be my only short cut"

Antony Worrall Thompson:

Ketchup and Worcester sauce

"I would also add to the list some anchovy essence"

Delia Smith:

Sainsbury's fresh bolognese and freshly made gnocchi

"This is a total cheat - but utterly gorgeous"

James Martin:

Supermarket's own-brand fresh stock

"It's my favourite thing at the moment. It makes a great sauce"

Sam Stern:

Marmite

"The best shortcut for stock is having the real thing around in your freezer whenever you want it"