Only people of a certain age - mine - and over are likely to remember Englebert Humperdinck. He sprang to mind when I went to eat in Belsize Park, and was reminded that the lantern-jawed one had an unlikely hit with a bizarre song called 'Les Biciclettes de Belsize'. Like much of life, it made no sense at all.

Just what is it about Belsize Park and music? Eighties rock band Marillion once sang a line about 'loving on the floor in Belsize Park' and Sir Paul McCartney recently regaled fellow diners at XO restaurant with an impromptu performance (before telling the waiting paparazzi to X off).

I never usually go quite so far north for dinner unless I have to. For an East End boy like me, it's a bit like a trip to the moon: it's trendy, it's scary and the local MP is Glenda Jackson, who once spookily starred in a film called, of course, The Music Lovers. But, on this occasion, I am glad I did.

My journey took me through St John's Wood with its enormous, ugly houses, replete with often absurd wrought-iron gates and dripping with tax-free wealth and pretension. And at first sight, XO seems to share that pretension.

You enter to a long bar, brimming with hundreds of bottles, over which the young and the chic are draped. Everything is black - and not just the décor. The staff are decked out in black clothes and adorned with fashionable glasses. One of them was wearing a pair that made him look just like Joe 90 - another character only those of a certain age will remember - and my inquisitive companion asked where he'd got them. Halfway through dinner Joe 90 appeared clutching his optician's card, which is what I call service.

Aided by such friendly attention, it soon became clear that the apparent pretension that strikes you on entering belies what turned out to be an easy, laid-back charm.

The restaurant is one of five owned by Aussie Will Ricker, which I suppose makes it part of a chain. The name XO apparently refers to a Chinese savoury sauce based on an unconvincing mix of dried seafood, ham, garlic and chillies. Oh, and is an homage to the famous brandy.

The food is fusion, which for the uninitiated can often mean confusion. Fortunately, the waiter was there to guide us through the menu. And what a treat it was. The crisply perfect rock-shrimp tempura and prawn and pork dumplings were so good we ordered extra. Only the spring rolls disappointed. Like spring rolls the world over, they were cold and soggy.

We ordered black cod but - unlike the décor - the fish simply wasn't black enough and was also a tad overdone, but my greedy companion ate it anyway. My prawn curry with ginger noodles was incredibly tasty.

Unsurprisingly, we couldn't manage any of the puddings but the list seemed ridiculously heavy - cheesecake and chocolate brownies - and not a natural companion to the rest of the menu. I certainly couldn't imagine any of the slender locals (Gwyneth Paltrow, Sienna Miller) spooning these into their delicate mouths.

The wine list was daunting, crammed with wines with the most extraordinary names and very expensive. We played it safe with Pinot Grigio, refreshing with the meal but probably not worth £39 (and it was one of the cheapest on the list). My companion was taken with the idea of a bottle of Bonny Doon to follow, just because he liked the name, but Joe 90 cautioned against it. We took refuge in Pinot Noir - unoriginal, it's true, but at £33 a comparative bargain.

All in all it was a great meal in a smart, friendly restaurant, and I'd certainly make the journey north again. And the celebrity factor? Pretending to do no such thing, I glanced around in a futile search for one, but alas, in vain. All I could see was a Seventies sitcom actor whose name I couldn't remember (although I am pretty sure he did a Rod Hull-style act with a blue bird).

How different it must have been the night Macca sang for his supper. Enviously, I let my eyes drift to the piano and tried to imagine which song he would have chosen. 'Baby's in Black', I suppose.