D.Sum², 14 Paternoster Row, London

Could a fledgling chain of dim-sum restaurants knock the steam out of this increasingly popular way of dining?

Manager Amy Chong says: 'We want to bring a fusion between modern dining and traditional dim sum' © Michael Franke

Has the steam gone out of dim sum as we know it? When the high street hijacks your favourite way of eating – be it pizza, burger, sandwiches or sushi – and turns it into a chain, you know it's all over. On the up side, you get uniformity, consistency and rigorous hygiene. On the downside, you get uniformity, consistency and rigorous hygiene.

Dim sum is the latest to join the chain-gang. When the Wagamama creator Alan Yau took dim sum to the mountain top at Hakkasan and Yauatcha, using master chefs to turn top-quality produce into chic dumplings day and night in glamorous, nightclubby surroundings, he really started something. Now the dim-sum bandwagon is rolling along in earnest. Funky chains Ping Pong (seven and counting) and Dim T (nine) are rolling out across the country. Even Harrods has a dim-sum bar in its food hall. In the meantime, Yau has sold Hakkasan and Yauatcha for £30m, and plans are afoot for global expansion.

And now D.Sum² pops up in the City, hoping the suited end of the market is big enough to warrant yet another chain.

Set up by an entrepreneurial seafood importer and several partners, it is a pastiche of everything from Chinatown's diners to the latest chichi modern pan-Asian palaces. So there is a big island counter for dim-sum dining on the glass-walled ground floor, and clothed tables in the more intimate space downstairs. The contemporary minimalism is "warmed up" with single roses in bud vases. Likewise, there is a menu of traditional favourites such as har gau, siu mai, char siu bao and turnip puffs, as well as a raft of Yau-inspired modern classics including black cod, soft-shell crab, and wasabi king prawns. And, yes, there is every Briton's favourite Chinatown dish of crispy shredded roast duck, with pancakes and sides.

If you call yourself D.Sum², then the dim sum, one imagines, would have to be good. Hangzhou, we have a problem.

Steamed lobster dumplings (£4.60) are large and very firm, with an unpleasant ammonia-like taste that is vastly off-putting. Things don't get much better with woo gok, or chicken and yam croquettes, (£3.30), which should have light, delicate shells covered with gossamer-fine fuzz, instead of thick, hard shells that suggest reheating. Scallop siu mai (£3.80) are edible if you try not to compare them with Yauatcha's versions, which have both flavour and texture, and Shanghai siu long bau dumplings (£3.50) have claggy pastry, mushy filling and none of that how-did-they-do-that hot broth inside.

This is lunchtime in the City, so while there is a perfectly decent wine list, not a soul is drinking alcohol. It's Voss mineral water or fizzy cola on every table, which is a shame, because they do a civilised tea service here. My green tea (£3.50) is fragrant with tiny chrysanthemum buds, and served in an elegant glass teapot.

Having written off the dim sum as poor, I risk a couple of main-course dishes. Ginger seared prawns (£11.80) sounds promising, but is just a bog-standard stir-fry of flavourless prawns in a gluggy grey sauce, and Hong Kong roast duck with plum sauce (£18) is poor value for unevenly cooked fatty duck in a thick sweet gravy.

Then, heavens to Betsy, I strike it rich with a platter of baby pak-choi cabbages the size of my little finger, sensitively cooked and topped with crisp fried garlic. The miraculous thing is that nobody has stuffed it up along the way, apart from serving it on a cold plate.

It's an odd place, with not much style, charm or reason-to-be, and its eagerness to be seen as contemporary has compromised the cooking and made it feel old-fashioned instead of modern. The beautiful baby pak choi showed what the kitchen is capable of, but unfortunately, so did everything else I ordered.

8/20

Scores: 1-9 stay home and cook, 10-11 needs help, 12 ok, 13 pleasant enough, 14 good, 15 very good, 16 capable of greatness, 17 special, can't wait to go back, 18 highly honourable, 19 unique and memorable, 20 as good as it gets

D.Sum², 14 Paternoster Row, London EC4, tel: 020 7248 2288. Lunch, Sun-Fri; dinner, Mon-Fri. Around £75 for two with drinks and service

Read Terry Durack's new column at independent.co.uk/eat

Second helpings: Dim sum to die for

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