The spiritual home of the potato scone is not the first place you would think of to open a sushi bar. But discerning Scots have taken to Oko like fish to water

Oko, 68 Ingram Street, Glasgow

Oko, 68 Ingram Street, Glasgow

The conveyor-belt sushi restaurant has been a godsend to TV drama directors. If they want to signal that their characters are glib media morons with goldfish attention spans, all they need to do is to plonk them down on stools in front of endlessly rotating plates of decorative raw fish, and Bob's your robot beer-dispenser.

In fact, although kaiten zushi, or revolving sushi, restaurants are still largely a London phenomenon, they have been enthusiastically adopted by a wider public than just urban trendies. The Yo! Sushi concession in Selfridges Food Hall is packed with ladies who look like they'd be more at home in San Lorenzo. Meanwhile, the chain's only branch outside London, in Kent's Bluewater shopping centre, attracts families who might once have lunched at McDonald's, but now look quite comfortable using chopsticks to stir wasabi into their dishes of soy sauce.

The market leaders, Yo! Sushi and Moshi Moshi Sushi, have been slow to capitalise on their success outside London, which has left the field open for enterprising local restaurateurs. In Glasgow, Stephen Ellis has just opened Oko, Scotland's first kaiten zushi restaurant, with backing from Simple Minds vocalist Jim Kerr (remember their big hit, "Promised You a Maki Roll"?). They're so confident it will take off that they're already planning a second branch in Edinburgh, with others to follow around Britain.

Oko occupies a large corner site in Glasgow's city centre, in the revitalised Merchant City. The design is a little more ambitious than Yo! Sushi's canteen-like minimalism, with lots of dark slatted wood and brushed chrome, but the basic formula will be familiar to anyone who has visited a branch of Yo! Sushi. There's the conveyor belt, with its price/colour-coded plates carrying a constantly replenished selection of prepared sushi; inside the belt, the open kitchen area, where chefs and lackeys labour to provide fresh supplies; and around it, stools pulled up to a high counter. Each place setting has its own water tap, and containers of soy sauce, wasabi and pickled ginger.

My guest, the writer and broadcaster Muriel Gray, had already been to Oko three times in the six weeks since it opened - a testament to the quality of its food, she claimed, rather than an indication of the lack of good dining spots in her native city. We chose seats at the counter rather than at one of the tables tucked away at the rear of the room, but took the precaution of positioning ourselves with our backs to the enormous street-level windows - conveyor-belt dining is a recent enough innovation in Glasgow to draw crowds of onlookers.

The majority of our fellow diners, though, had chosen to sit at the conventional tables, perhaps self-conscious about the "see and be seen" aspect of the experience. They included a few business types and a group of women, spectacularly festooned in jewellery, shopping bags and showy accessories, whom Muriel identified as South Side Mall Rats, a uniquely Glaswegian sub-species of the Ladies Who Lunch.

The fact that food is available the instant you sit down is both the attraction and the drawback of the conveyor belt restaurant. Yes, you can eat at your own pace, rather than according to the dictates of the kitchen. But if you happen to be a complete pig, your own pace might be inadvisable, leading you to collapse in a satiated heap after a 10-minute feeding frenzy.

Conscious that we should spin out our lunch for at least half an hour, and not just grab whatever passed under our noses first, we started with a few dishes prepared to order from the menu.

The short selection of hot dishes includes gyozza (savoury dumplings, fried or steamed), katsu (chicken or fish, breaded and deep-fried) and the more familiar tempura, teriyaki and yakitori. Muriel's chicken udon soup was as pretty as a magazine cover, twinkling with sliced red chillies, seaweed and chunky mushrooms, which parted to reveal a tangle of thick noodles in broth. She loved it - but then she had already ordered it on each of her previous visits to Oko. My salmon teriyaki came in a small portion (still good value at £3.25) and was expertly cooked, seared orange and crisp, but sweetly pink within. In a minor concession to local taste, it was perched on a round cake of mashed potato, a combination which worked remarkably well.

Also made to order are temaki - fist-sized cones of shiny black seaweed stuffed with rice and a choice of fillings. My lobster and avocado selection was well-filled with (rather dry) lobster meat, sweetened with some kind of mayonnaise dressing; the avocado slices protruded wittily from the parcel like a pair of lobster claws. Muriel's salmon roe and cucumber temaki was a sensuous combination of textures, the firm seaweed wrap yielding to the brilliant explosions of jewel-like roe.

Then for the main event, the sushi. Oko has brought in the chef from Yo! Sushi in Harvey Nichols to head its team, and sources the freshest available ingredients. Scottish fish is used wherever possible, supplemented with specialist imports from Japan and the Far East, and the results are extremely impressive.

As the dishes aren't labelled, it's hard to provide a full gloss on what we ate. But all of it was miles better than the tasteless, over-chilled gloop that passes for sushi in supermarkets and sandwich chains.

Notable among the maki selection (the cylindrical ones, in which the filling and rice are rolled in dried seaweed) was a salty and intense number made with salmon and flaked salmon skin. The best of the nigiri (lozenge-shaped blocks of rice topped with raw fish) featured uncooked mackerel dusted with spices. Everything tasted fresh (the least you expect of sushi; you're in trouble if it isn't) and presentation was thoughtful. Ohitashi (pressed spinach), for example, which can be bland, was enlivened by a dusting of sesame seeds and a soy vinaigrette.

We finished with a couple of sinful selections from the westernised pudding menu. Muriel's was a Japanese version of summer pudding called ogashi, which was overly sweet. "I only licked the spoon and it's given me a migraine," she moaned. My fruit spring rolls were gorgeous, though, filled with papaya and banana, with a vanilla syrup for dipping.

Our bill came to £40, including excellent coffee, and soft drinks from a list strong on designer beers and New World wines. It must be the only kaiten zushi restaurant in the world where Irn Bru and Diet Irn Bru take their place on the drinks list alongside Asahi beer.

Oko, 68 Ingram Street, Glasgow (0141-572 1500). Daily 12 noon-12 midnight. Disabled access. All cards except Diners accepted