5a Air Street, London W1 (020 7406 3980).
Meal for two, including wine and service: £150
If a city gets the restaurants it deserves then London has clearly been a very good girl of late. At Hawksmoor Air Street even something as simple as the anchovy hollandaise gets me excitable. You could easily slip into a hotel room with a sauce boat of that and a consenting adult and lose a whole afternoon. It's luscious and just one of many thrills in an extraordinarily assured opening. Of course, the Hawksmoor team should know what they're doing by now. The restaurants that have preceded this – in Shoreditch, Seven Dials and Guildhall – have proved that it's possible to dedicate a kitchen to seared bits of aged cow without assuming a faux American accent; that there really is such a thing as a British steak house.
This new outpost adds fish to the repertoire. It occupies a grand curve on the first floor of a Regent Street terrace previously plagued by unworthy businesses. There was the grim pan-Asian tapas joint Cocoon – they should have stopped at the first syllable of the name – followed by a "sustainable" sushi place that lasted just months. Now it has been transformed. It is pure Art Deco, from the beautiful leaded windows to the polished wood veneer and the banquettes. Poirot would be happy here. Then there is the floor. There is no more parquet to be had in Britain. It's all in Hawksmoor Air Street.
What really matters is the menu. There are still their superb steaks, available in cuts from "reasonable", through "bring a friend" to "bigger than your head", seared by a kitchen that understands the ways of meat. There are the glories of bone-marrow gravy, a proper frothy béarnaise served still just warm, and that absurdly good anchovy hollandaise. Their triple-cooked chips are all snap and crunch and sigh. But what lifts this Hawksmoor is the fishy element, put together with the assistance of Mitch Tonks (of the OFM award-winning Seahorse in Dartmouth), who has helped them to negotiate the rapids of sustainability.
The result is everything you would want it to be and quite a bit more. There are queenie scallops, lightly battered and deep fried and served with a coarse tartar sauce. This is pimped finger food: the £8 serving is generous, but I could still have devastated another bowl full. Brixham crab on toast with their own mayonnaise is fresh and sweet and shell-free. We find ourselves humming happy tunes at our starters.
Alongside our 400g rib eye we get the "roast shoulder" of turbot. It's a stonkingly good tranche of fish, roasted on the bone then finished over the grill to give a light char, and clearly comes from a large animal, which is as it should be. The big fish, which have had their chance at replenishing the population, are the most sustainable option. Alongside this we order a side of Jansson's temptation, a Swedish dish, interleaving scalloped potatoes with salted fish, onions and cream, and then long cooked. It's what greedy Swedes do on endless dark nights. I'm not complaining that it's made here with salted anchovies.It's the best version I've ever tried. You could invite it into the hotel room along with the anchovy hollandaise. We finish with their peanut-butter shortbread with salted caramel ice cream – it was a light lunch – and a champagne jelly with grapefruit and orange, and a mandarin foam. At the end they bring salted caramel "Rolos" made with properly tempered chocolate that snaps to reveal the gooey innards. The mayor's office should denote these a London landmark.
You will pay for this. You will pay the sort of money that will make you gulp. And yet I would still call it value and argue that the removal of stupidities like thick napery and over-heavy glassware simply adds to the experience. (That said, the wine list does begin below £20 a bottle and has good choices by the glass.) Like everyone who does my job, I am regularly criticised for not getting out of London enough; I run at about 45% outside and often find good things. But the fact is that nowhere else in Britain could support a restaurant of this quality. I suppose I could lie about that, to protect regional pride, but really, what's the point? So save up, for as long as it takes. Book a night in the smoke. Eat here. It's worth it.
Email Jay at jay.rayner@observer.co.uk or visit theguardian.com/profile/jayrayner for all his reviews in one place
