Square Meal Guide 2009 (1 star)

"Injecting Knightsbridge glamour into Square Mile power dining was a shrewd move for Harvey Nichols, since the chain's City outpost is equally convincing for wheeler-dealing lunches & leisurely chill-outs.  The imposing former banking hall is tricked out with red leather chairs and abstract artworks; at lunchtime the decibels can become excessive, while evening sees the mood & the lights turned down.  On our visit the kitchen delivered a succession of dishes that looked and tasted spot-on: langoustines with a shot glass of warm, saffrony langoustine bisque for instance, & halibut jazzed up with splurges of intense tapenade & zigzags of sweet potato & orange puree.  Perfect grouse with savoy cabbage & truffled breadsauce proved the kitchen can dispense comfort as well as high fashion, while a grown-up Black Forest gateau provided a fitting conclusion.  The wine list teams noble French bottles with quirkier offerings such as an Austrian Pinot Rose from Weingut Weininger."
 

The AA Restaurant Guide 2009

"The Square Mile houses several restaurants, but few as impressive as this one. Once the Bank of New York, its lofty ceiling and vast spaces make a palatial backdrop for fine dining. For a more discreet experience there is the Conservatory, separated from the main restaurant and ideal for meals a deux.

The menu offer a lively choice of dishes inspired from around the globe, with the accent on detail and flavour. Starters like ballontine of rabbit, date and Parma ham, with a rabbit veloute and celeriac remoulade make a punchy prelude to chargrilled swordfish, borlotti bean and sweet pepper ragout, with chorizo-stuffed baby squid. Harvey Nichols quality is stamped throughout. "

View London, June 2008 (5 stars)

"Tell friends who aren't au fait with top-end London dining (or are hard of hearing, or both) that you are 'going to Prism' and they are likely to ask what crime you have committed. In fact, it would be hard to imagine an experience less like being banged up in Wormwood Scrubs - unless brilliantly executed, complex but never silly food served impeccably in a stunning yet soothing setting has become the order of the day at our penal establishments.

The Atmosphere
From the moment you walk in, a meal at Prism feels special but never intimidating or overly formal. This is down to the staff who, despite being super-slick, offset the grandeur of the setting with unfailing friendliness: you feel they genuinely want to do all they can to make your experience memorable.

The Food
There are eight starters and eight mains. A fillet of red mullet escabeche (£14.00) is delicate and juicy, and surprises by arriving warm. Its accompanying salad of minutely diced Jerusalem artichoke, potato and sweet red pepper with palourdes (clams) delivers the perfect, light, summer starter. Even better is a trio of huge, crusty scallops (£16.50) on a silky caramelised cauliflower puree with diced apple, daikon (Asian radish), cress and truffle.

The mains are similarly faultless. Melting fillets of plaice, steamed with lemon, thyme, and mussels, come with a courgette flower, sweet pickled crab and sauce vierge (£26). Every component pulls its weight: this is complex, confident cooking of the highest order. Saddle of Pyrenean milk fed lamb (£31.50) is three moist and tender pink noisettes with a herby stuffing. They contrast sensationally with confit of lamb shoulder, flavoursome almost to the point of being gamey, served in a cannelloni tube. A side of homemade chips (£3.75) are crisp without and floury within, and, as promised by the waitress, easily enough for two. French beans, also £3.75, are a similarly generous portion, perfectly al dente and laced with melted butter.

The Last Word
Anyone spending around £80 a head for a three-course meal with modest wine has a right to expect something memorably marvellous. All too often that isn't the case, but this place totally delivers. What's more, because the City is deserted in the evenings, getting a table shouldn't be much of a problem. (You'll need to go on a weeknight, however, as Prism is open only for private hire at weekends.) Forget the overpriced, over-populated West End for once and head east to a restaurant where the kitchen's beautifully realised ambition is as lofty as the dining room's ceiling.