Fusion may be out of style, but La Contenta in central London is reinventing the whole concept. Richard Johnson appreciates an Italian renaissance

I prefer (and, remember, this is just one man's personal truth) the thin crusts of Rome to the doughy crusts of Naples. But the pizzas of La Contenta are from another place altogether - the darkest depths of my imaginings. They arrived from the wood-fired ovens, plumped up like pillows, slathered in dolcelatte, rosemary and caramelised red onion. But I'm getting ahead of myself. I must begin at the beginning.

La Contenta feels like a New York loft. I would say a New York gallery, but there was no art on the rough plaster walls. Just natural sunlight, spilling through the huge, arched windows. The kitchen was open plan - the place, clearly, had nothing to hide. Chef Giancarlo Vatteroni had bought a new pizza oven, and he wanted the whole world to see it.

Giancarlo (Gianni to his friends) only buys the best for La Contenta. Take the olives. The appetising little fruits were cured in lime, rather than brine, and had a really clean, vegetal taste. As I picked at them, the place started to fill up - with single men ordering the spaghetti. I felt no pity. No man is lonely while eating spaghetti. It requires far too much attention.

The menu at La Contenta is Italian Fusion. I say that, but nobody uses the f-word any more - fusion is out of favour. It's not easy to apply the techniques of one cuisine to the ingredients of another. After all, as the American humourist Fran Lebowitz said, people have been cooking for thousands of years - if you're the first to think of adding lime juice to scalloped potatoes, there's probably a good reason why.

Italy isn't really a country - it's only been in existence for 140 years. It's a series of regions, each with its own style of cooking. And those styles are sometimes rigid. If you're from north-east Italy, and you don't put a ham knuckle bone in your tomato sauce, your sauce is no good. So, thank heavens for chefs like Gianni, who think big. He recognises that our idea of Italian food is, in itself, "fusion".

Gianni calls his cooking Italian Progressive. So, the deep-fried lamb ravioli (£6.40) arrived reclining on a salad of mint, with a dressing of chilli lime. It was actually more like a samosa - light and crispy, without a trace of oiliness. But fusion or no fusion, it was the flavour that was exciting, not the concept. And, although the textures ran amok, the taste remained beautifully grounded.

The roast duck breast (£13.50) arrived on a heap of slow-cooked red cabbage. It wasn't handsome to look at, but it had a lovely character, and the grilled figs gave it a real Asian quality. Asian cuisine is most often associated with fusion because its pronounced elements of hot, sour, salty and sweet produce a layering effect. That's why every mouthful of the duck tasted different.

The menu offered some dishes for two to share, including the sea bass roasted in a rock salt crust (£12.95). When my tagliata (£15.75) arrived, I thought I had pointed at the wrong column. There were enough thin slices of rare organic rib steak, re-grilled on radicchio trevisano, with shiitake mushrooms, rocket and shaved Parmesan, to feed AC Milan. And the reserves.

Normally, I'm with Mae West: too much of a good thing can be wonderful. But the tagliata frightened me. Then I tried it. Tagliata comes from the Italian tagliare, which means "carved". It's a technique which involves cutting the meat into thin slices, and then drizzling it with seasoned oil. It was meltingly tender, and contrasted sharply with the crisp, peppery rocket. So I told the boys from AC Milan to get their own.

The tagliolini nero (£7.90) came with a fish ragu and battuto. It's odd, to list battuto on a menu. It is a mince made up of onion, celery and carrot - and perhaps bacon fat or pancetta - fried lightly in the early stages of a dish to add flavour. To see it written down smacks of a desire for authenticity. Maybe Gianni was expecting Mama and Papa for dinner on the day he printed the menu.

Maybe, like the best Oscar acceptance speech, it's nice to mention the little guy. So, yeah: "Thanks battuto. Without you this wouldn't have been possible. And I would like to thank pasta water" etc etc. But the long, paper-thin ribbon noodles melted down into a comforting, robust fish stew. There was something missing - at least I didn't show myself up by asking for the Parmesan.

There's an unwritten law that Parmesan should never be incorporated into a seafood dish when pasta or rice are involved. But that's exactly why I should have asked for it. La Contenta is about progressive thinking. And just because, in Italy, they don't serve salad with pizza, or cappuccino after 10am, doesn't mean we have to follow suit in Britain. Hell no.

The only dish that didn't work was the dark chocolate cake with pina colada granita (£4.75). Granita should resemble snow, sparkling with colour. And it should carry sharp flavours - like grapefruit, red wine or watermelon. I've had it served as breakfast, in the hot days of August, with biscotti. And spooned onto brioche. But the waxy chocolate cake demanded something creamier. After all, there's a world of possibilities out there. E

La Contenta, 90-92 Wigmore Street, London W1 (020-7486 1912)