titlehere; Jamie Oliver is more than a chef; he's a health guerrilla and a political dynamo, writes Eve MacSweeney.(Interview)

Byline: Eve Macsweeney

Hi, tiger."

This is Jamie Oliver's greeting-standard for all comers-as he stands in the lobby of the Mondrian in Los Angeles making plans for his day: luggage here, mates there, lunch at a restaurant opened specially for him by the Japanese chef Hiro Urasawa, a photo shoot, then home to London on the red-eye. But first, breakfast, which today is just a cup of tea so that he can pay Urasawa the compliment of an appetite.

Oliver, who is just 30, occupies a place in the British consciousness far more resonant than merely that of a celebrity chef. But today the man who is often discussed in the context of an imminent knighthood looks like your kid brother in his rumpled hoodie and jeans, with blue-blue English eyes and what used to be called footballer's hair (a cousin of the mullet, short on top and long at the sides, with sideburns) before footballers looked like David Beckham. As we sit and stir our tea in the rain-soaked Skybar, I'm expecting the laddish charm familiar from Oliver's cooking show, The Naked Chef (so named for his pure ingredients). What I hadn't quite reckoned on was the relatively subdued, thoughtful, inspired, genuinely charismatic man in front of me with the energy to turn a whole country's food habits around.

A celebrity he is, to be sure. He flew in to cook an exclusive Oscar-week dinner the previous evening at Soho House-a mirage of the New York and London clubs that materializes for one week a year in a private residence high over Sunset. After working in the improvised tented kitchen to oversee his menu of tuna carpaccio, line-caught sea bass, and bakewell tart, preceded by numerous amuse-gueules to help wash down the champagne, he changed out of his chef's whites and into a fuchsia-lined Paul Smith suit to mingle with his dinner guests well before the meal was served. All the key British girls were there: Sienna, with a posse of young English actors; Keira, with her mum; his pal Madge, her hair carefully crimped into place, who sat at Jamie's table with Guy Ritchie.

But being on friendly terms with famous people is not what gets Jamie going. His media-genic qualities, give or take a liberal sprinkling of profanities, were spotted by a sharp-eyed TV producer when he was working at Ruth Rogers and Rose Grey's fabled London restaurant, the River Cafe. At 22 he was given his own show, which was cooking-as-reality-TV, designed to convince the British public, especially blokes, that it was quite doable to stir and bash a bit of produce around without looking like a total wuss. Oliver's exceptional people skills came in part from growing up in Essex in what he describes as "one of the first gastro-pubs." His father served wholesome fare like stews and grilled fish alongside the pints of bitter, and Jamie, as a twelve-year-old, would help run the kitchen by telling the grown-up staff what to do, a job that doubtless called for inventive reserves of tact.

More than an infectious communicator about everything to do with shopping for, and preparing fresh, simple dishes, Jamie is a food crusader. Good, nutritious meals are not just a pleasure in his eyes, they are a force for rehabilitation and an imperative for public health. First came Fifteen, a restaurant and charitable project he set up to turn disadvantaged youths into chefs, accompanied, as are most things Oliver does, by a TV show. "I'd gone from being a sous-chef at the River Cafe to flogging five-and-a-half-million books three years later ...