Just like the cult 60s caper filmed nearby, seeing XO with its chrome and bold colours is a flashback to the past. But its efficient service and sublime food make it a must for contemporary diners, writes Joseph Connolly Smashing Time. It s a little-kno

Just like the cult 60s caper filmed nearby, seeing XO with its chrome and bold colours is a flashback to the past. But its efficient service and sublime food make it a must for contemporary diners, writes Joseph Connolly

Smashing Time. It's a little-known film, now something of a cult - an enjoyable scamper through the Swinging Sixties in London, actually made towards the end of that heady decade, which gives it a life and immediacy that later evocations inevitably lack. I was once marooned in an airport lounge in Nice with Michael York, the film's leading man (amply complemented by Rita Tushingham and Lynn Redgrave) and he told me that apart from Logan's Run, he is asked more about Smashing Time than any other film he's ever made. And while a bit of it was filmed on location in places such as Carnaby Street, a good deal more was shot in Belsize Village. The large corner building next to the Greek restaurant Retsina - crumbling for many years and now obliterated by scaffolding, plastic netting, and yodelling builders - was dressed as a very fab clothes boutique called Too Much. Everything was overpriced (geddit?) but it barely mattered because no one ever paid for a single thing (this a satire on Biba, renowned as a magnet for shoplifters).

All this passed through my mind, as such nonsenses constantly will, while I sat bang opposite at a window table in XO, the newish and groovy Pan-Asian set-up (offspring of Notting Hill's ultra-hip E&O) which in days of yore was the Belsize Tavern. There is an irony that the d�cor (so utterly on trend) would have seemed laughably dated in the days of Smashing Time, because what we have here is a perfect snapshot of not 2009, but fifty years earlier. Spare and white with bold bands of red and yellow, the multi-branched ceiling lights in black and chrome very much echoing an Alexander Calder mobile (when this still denoted a kinetic artwork, and not a bloody phone). Odd, really, the current passion for retro interiors. Can you imagine a fashionable joint during the prime of our own dear Cliff Richard taking its design motif and vocabulary from 1909? Well quite.

My wife and I were eager for grub, though still I paused to have a nose around the attached little upmarket and very popular caf� and takeaway, XO To Go: a good deal of the menu is available here - sound idea, I suppose. And next door to that, oh crumbs - what a curious place: 'Gentlemen's hairdressing by appointment only to gentlemen'. There's lots of copperplate script all over the dark and firmly barred exterior: 'Private and Personal club style atmosphere by appointment to radio, TV, stage and film personalities, businessmen and professionals'. And although I am none of these things, still I hovered, seduced by an unspoken promise: could they, I wondered, do me a very quick friction and blow-dry? The tug of my wife, however, reminded me we were eager for grub, not rub.

Being a Monday lunchtime, XO was pretty much empty - just a party of three to the left of the long and classy bar. We considered dim sum as I glanced through the window at the few people at tables on the pavement, including a mother with her baby, maybe three months old. You could see he was confused: he knew it was 2009 - it said so on his birth certificate - and yet all around was 1959. When I am fifty, he was rapidly calculating, will the present year eventually be reflected ...? He shook his head and cried: such dim sums were beyond him.

My wife ploughed into the set three course lunch, which is a remarkable steal at �15. Her miso soup was just smoky enough, the thin sliced mushrooms floating, peas to be found deeper on down - and then a single cube of tofu, simply lurking. My Prawn Har Gau was a full-fat delight: four large prawns made indecently plump and luscious by their translucent dumpling jackets, fluted and fanned like the logo for Shell and given a kick by the soy sauce dip (and no, it didn't cross my mind to offer a taster). And anyway, she was busy with her Summer Smash (too much!) - a non-alcoholic cocktail of strawberry, apple and cranberry, charged with crushed ice with a chunk of cucumber impaled on the rim. It reminded her, she said, of the syrup in Smedley's tinned strawberries (and this is evidently a good thing). And as I sipped my glass of Italian rose, which was okay, I had a look about me. A long ribbed red leather banquette, strikingly similar to those as dozed upon in the House of Lords, and pleasing ironwork dividers alive with what looks like Mary Quant's famous daisy. Yet more time warp. There are curved black wooden bars for leaning on, and beneath them a series of very low and chubby upholstered stools; I don't know - might have been bongos.

My wife's very generous Phad Thai came with the option of chicken or prawn, but she went for just the straightforward stir-fried rice noodles, egg and bean sprout thing, this made sticky with a good fish (maybe oyster) sauce, the chopped chilli and peanuts very sensibly on the side. This was good, as was the accompanying Pak Choi, gooey and crunchy all at once. I had beautifully presented Korean barbecued chicken: sublime, this. A whole very tender breast infused with flavour, topped with a rich and deep barbecue sauce (owing nothing to an XO cube) and diced no doubt dangerously swiftly with a demonically sharp knife. Singapore noodles were very good with that - the vermicelli not claggy, nor too heavy on the ginger and curry, and decently studded with prawns. The portions are huge here - so much so that my wife declared that she could not finish (virtually unprecedented, this): could not, was the emphatic message, go another mouthful. Then the trio of puddings arrived - all she could do was sigh with regret, mournfully shake her head and then just dive into them. Very nice too - a wedge of chocolate brownie, a cube of cheesecake, and a little bowl of vanilla ice cream which was oddly beige, on account of it turned out to be praline: yummy, though.

This is a swish and well-run place: charming and efficient staff, reasonably priced, and I can see that it would be a blast on a busy evening (as every evening seems to be, I hear). The music, well ... late night jazz is not right at lunch time, and country and western is not right in any circumstance whatever, and particularly if it's a whining woman whom you yearn to quickly murder.

And so to loo: tip-top - a nod to the orient in the pale jade crackle-glaze tiling. Care to guess who I met there? The chef. He was not Pan-Asian - hailed from nearer to Bolton, at a guess - and when I praised his cooking, became visibly bathed in pleasure and gratitude: a dedicated man. That Korean chicken, apparently, is marinaded for three whole days before being char-grilled - and if he ever dares to remove it from the menu, the denizens of Belsize rise up and take arms. Oh yes and one more thing about that loo: you pull the chain! I know! Haven't done that since ... ooh, I don't know, the Swinging Sixties, I suppose. Smashing Time...

Joseph Connolly's latest book is Faber and Faber: Eighty Years of Book Cover Design

(Faber and Faber, �25). www.josephconnolly.co.uk.