When the first Cha Cha Moon opened in Ganton Street last summer, it was said that a second branch of Alan Yau’s bargain Chinese noodle joint would soon follow at Whiteleys. But it’s been delayed and delayed, finally arriving only this week, with the formal opening tomorrow.

Foodwise, nothing much has changed. Where originally all the dishes cost a bargain £3.50, prices now take account of portion size and the cost of ingredients, although remaining incredibly cheap with a £5.50 top price. There are a few sides but no starters or desserts. You come here for a quick bowl of good, cheap noodles — either in soup, wok-fried, or “Lao Mian”— and then you move on.

The new Cha Cha Moon, up on the second floor of Whiteleys, is fully part of the restaurant concourse, not cloistered away like Rowley Leigh’s Café Anglais. The view out is uninspiring, the neighbours dull chains such as Bella Italia and Café Rouge. It’s a pity. The restaurant itself would do credit to much more appealing surroundings than a tired shopping centre now hugely outflanked by Westfield.

The “executive architect” is Kengo Kuma, who aims “to recover the tradition of Japanese architecture”. Among his works in Japan and China, he has built bamboo houses, citing bamboo’s appeal as a raw material that can’t be processed. He’s inspired an extraordinary room, worth a visit on its own as a piece of architecture, never mind for a good-value meal.

Whether this effortful design can possibly provide a template for a whole chain of Cha Cha Moons — Yau aims to open 10 or 20 in London over the next few years — is another matter.

Undulating over the ceiling and down the back wall is a great wave of aligned bamboo rods, giving strict direction to the room, echoed by a slightly stripey lino flooring. The amazingly long, thin tables are surfaced with milled bamboo too, a sleek material, unlike the rough wooden and brick surfaces at Ganton Street.

For the seating, there are smaller, separate benches this time, made from a single piece of black steel with intriguingly twisted legs and rather hard edges. So although this remains communal dining, one of Yau’s great contributions to British eating-out habits, now it’s in smaller groups.

At one end of the room there’s a surgically high-tech kitchen open to view; at the other, a similarly sharp bar. Both also present mirrored surfaces to the room, so that its length seems to stretch out indefinitely. It’s a thrilling minimal take on Orientalism, conveying the restaurant’s mission as a whole.

But there’s a real oddity here, perhaps even a mishap. To stop the bamboo from warping and splitting, it has to be constantly — every minute or two — spritzed with mists of water from spray guns in the ceiling. At first, it’s completely disconcerting, as though you’re in a Bond film about to be taken down with knock-out gas. Each time it happens, you feel both a faint drizzle and a little drop in temperature. But maybe it will be refreshing in summer, maybe it will even become a feature.

Service is brisk and assiduous. Only the thick-skinned will take their time here. And the food? Not just great value but I think actually good too. A BBQ duck noodle (£5) came with four really good chunks of duck, some pak choi, a scattering of intriguing little red “wolfberries” (the goji berry, sometimes taken medicinally) and yummy noodles, although the cloudy stock was disappointing. Garlic chinese chive (£5.50) was a whole dish of appealing. mildly flavoured chives, making a refreshing green vegetable.

Yau himself rates the Singapore fried noodles as “the anchor dish”, “the raison d’être of the overall menu strategy”. It was unequivocally great stuff, a big serving of rice thread noodles, with smoked chicken, red and green peppers, prawns, bean sprouts, some egg and cabbage, quite hot and funky. A dish I’d be happy to eat over and over again, it costs just £3.75, a bargain when compared to the £6.80 currently charged at Yau’s previous creation, Wagamama, for a directly comparable, slightly less rewarding Yaki Soba. Throw in a little carafe of the robust Portuguese red at £4.90, say, and you’ve got a really jammy lunch or quick dinner for well under a tenner.

What we have here is state-of-the-art recession-restaurateuring. Although as cheap as it gets, it’s just as interesting and satisfying to eat here as at any restaurant at any price whatsoever.