Bread Street Kitchen, One New Change, 10 Bread Street, London EC4

One of the many mysteries surrounding Gordon Ramsay is why his cut-the-crap, no-nonsense TV persona is so far removed from the prissiness of his restaurants. On screen he's all blood, sweat and shouting; in his dining rooms it's all lilies, amuse-bouches and murmuring.

Now comes Bread Street Kitchen, the Ramsay group's latest mega-opening in the City, and this time he's doing things differently. It's informal, it's democratic, and it takes its aesthetic from the lofts of Shoreditch rather than the gilded salons of Paris. In short, Gordon's gone groovy. "Drop in and say hello," Bread Street Kitchen's website chummily entreats.

Occupying a substantial slab of One New Change, a shiny development of offices and shops in the shadow of St Paul's, Bread Street Kitchen is just a few steps from Jamie Oliver's Barbecoa, which got there first and nabbed all the cathedral views. Gordon's place is bigger and buzzier than Jamie's, positioning itself as a Wolseley for the City and open from early morning until late at night. As it turns out, the all-day dining option means that a lunch can drag on almost till teatime. But we'll come on to that.

Bread Street Kitchen opened a year later than planned, and apparently cost £5m. When you walk in, you can immediately see why. This isn't a restaurant, it's a small town, with its own microclimate; a monumental space, seating 250, criss-crossed by gantries and flooded with light from wraparound 20 foot-high windows.

Designers Russell Sage Studio have showcased the building's concrete struts and exposed ducting to create an authentic industrial feel, and brilliantly scaled up the reclaimed, shabby-chic look to fill the space, using old school chairs, laboratory stools, and enough vintage Anglepoises to fill a Design Museum retrospective. Sure, it's a pastiche, but it's a brilliantly convincing one – so much so that my lunch guest asked, "What was this place before?", even though he'd just walked in through the new development.

The menu is similarly on-trend, to the extent that it reads like a synthesis of influences from other people's restaurants – here a bit of trad Brit meatiness, there some Tuscan rusticity, some dishes from the raw bar, some from the wood stone oven, all leavened with buzz-word ingredients and concepts –burrata, meatballs, macaroni cheese as a side dish. If this was an episode of Kitchen Nightmares, Gordon would take one look at the 20-plus starters and similar number of mains and say, "Guys – focus on what you're good at!".

In fact, nearly everything we ate was good, from super-crisp potato croquettes filled with braised pig's cheek, to a nicely-balanced crab linguine, warmed by a breath of chilli. Steaks and burgers are the new gold standard of London dining, and BSK's burger (£11.50) is a worthy contender, made with ground short rib, for a notably juicy bite and topped with melted Bermondsey Flier cheese. Hand-cut chips, ordered as a side, had the flavour and crunch that comes with triple cooking, though they weren't billed as such. A pie – actually more of a hot-pot – of slow-cooked shank of Herdwick mutton under a mashed potato lid, looks set to become a signature dish, from the way it was flying out of the kitchen.

Our waitress was obviously unfamiliar with the menu – she didn't stop us ordering mashed potato as a side dish for a potato-lidded pie – and it took four attempts to make her understand the words 'Chianti Classico'. "It's playing up," she explained as she stabbed desperately at her handheld device; only some of the orders were reaching the kitchen. "Hopefully yours has gone through," she offered.

It hadn't, and our lunch lurched forward in fits and starts, with one starter arriving a full 15 minutes after the other. Our wine was taken to the wrong table and, 90 minutes after arriving, we were still waiting to order puddings. In the City, more than anywhere else, lunch has to be quick, but the euro could have collapsed during the time we were there.

Our lunch, now drifting seamlessly into afternoon tea, ended with a voluptuous chocolate tart, served with salted caramel ice-cream, and cinnamon-dusted ricotta beignets – oddly successful, considering they're basically cheese doughnuts. But by that stage we were rather desperate to leave.

Of course, in the opening week of a huge new restaurant, things are going to go wrong (though if anyone should get a launch right, it's Gordon bloody Ramsay). But the response from the managers – young and Hoxton-y, in their skinny brown suits – was to ignore us, despite our clearly signalled distress. No dish was taken off the bill, no compensatory glass of wine offered.

It was the inverse of the normal problem with Ramsay restaurants, where you get impeccable service in a sterile atmosphere. Bread Street Kitchen is a potentially fantastic restaurant, exciting and – yes! – hip. But they don't have a clue how to look after their customers. And unless they bring a little uptown courtesy to their new downtown operation, I won't be dropping in again to say hello anytime soon.

Bread Street Kitchen, One New Change 10 Bread Street, London EC4 (020-7592 1616)

Food
Ambience
Service

Around £50 a head for three courses, before wine and service

Tipping policy: "Service charge is 12.5 per cent discretionary, of which 100 per cent goes to the staff; all tips go to the staff"

Side orders: City slickers

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