Cruse
9, 62-63 Halliford Street, London, N1 (020 7354 8099)
Meal for two, including wine and service, £90

Let me remind you of the rules. Never eat in a restaurant on a boat. Dinner can't be good when the floor is at risk of tilting and the air smells of septic bilge. Never eat in a revolving restaurant. The view, and its passing, will always be more important than the food. Finally, never eat in a fusion restaurant - unless it is owned by Peter Gordon. He is the one chef, first at the Sugar Club, later at Providores, who has popularised a whole culinary genre only he is good at. In the Nineties, fusion became a euphemism for overambitious, generally crap chefs attempting to introduce bits of the world to each other which had no business sharing plate space. Most of what resulted couldn't be called dishes. They were the culinary equivalent of Tourette's: a lump of innocent protein surrounded by sudden violent expletives of flavour which were shocking, but not in a good way. Think Szechuan pepper-crusted rib-eye steak with fish sauce and roasted garlic beetroot mash. Think battered haddock with lemongrass and fennel rosti, with a chocolate chilli dip. Or don't think of them. I just did and I feel queasy.

Naturally all of these rules have their exceptions. You can eat well on a boat - if you own the boat and employ the chef. And you would eat well in a revolving restaurant if it was the one at the top of the GPO Tower because the view would justify everything - except those selfish pigs at BT won't let us. As to the fusion-food rule: the exception appears to be offered by a quirky neighbourhood place in the arse end of London's Islington called Cruse 9. I asked about the name. It had something to do with the address where the two founders lived together at university. Hell, it's their restaurant. They can call it what they like.

It is a simple place of hard surfaces: dark tiled floors, a wall of white, a wall of glass. The colour comes on the plate. You know you are in interesting - read dodgy - territory when you are offered white chocolate and chilli bread. The headline news is: it works, mostly because those two tastes register separately, the soothing sweet of the chocolate first, the heat of the chilli later, all of it borne aloft by a yeasty, porous bun. It was a bold start to a meal which, despite the worrying signs in the menu descriptions, delivered few misses. A chorizo 'cassoulet' was nothing of the sort, but it was a dense knuckle-duster of a stew full of caramelised vegetables and mined with chickpeas, which almost made me understand the point of their blandness. In a bowl of mussels with a powerful salty cider-rich liquor, the curious touch was a beard of deep-fried seaweed. Why hasn't somebody thought of this before? Seaweed and mussels make sense together, and it's passing pleasant to have a crisp crunch before the soft squidge of the seafood.

Mains read long, and ate simply. How about 'Lamb rack stuffed with kofta, served with spiced aubergine, fresh mint raita and pickled cucumber'? It sounds like something dreamed up on that risible BBC2 show Food Poker after a grim turn of the cards. There was no need to be afraid. Stridently seasoned but accurately cooked lamb, two discs of excellent kofta, nice pickled cucumber and raita (maybe the plate would have looked naked without it). A slab of seared swordfish came with a pile of noodle-like ribbons of crisp acidulated mooli (a kind of radish), alongside water chestnuts fried in chilli butter. All of these were offered with wine pairings by the glass - something butch and Italian to go with the chorizo, a viognier with the swordfish - which delivered.

It's not cheap, but then this is Islington, where even being poor is expensive. But it is accomplished, and the two chaps in charge, who probably bonded over the male-pattern baldness they knew lay in their future, know how to provide cheery, engaged service without being there when you don't want them. Gosh, they even commit one of my cardinal sins - adulterating a crème brûlée, in this case with Cointreau - and because the basics are right I can forgive them. True, a stodgy mango bread and butter pudding suffered for being cold. But that's the best I can do by way of substantial criticism. Cruse 9 may sound like a rackety gay sauna. It turns out to be a rather nice restaurant that gives fusion food a good name.

· Jay Rayner's book The Man Who Ate The World: In Search of the Perfect Dinner is published by Headline at £16.99