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'It's ages since I've stared at a menu for so long without finding something I want to eat. But I forgive everything because of the wine list'
There are so many extraordinary things about this restaurant that I'm not quite sure where to start. Let's go with the obvious, then: the 1927 Rex Whistler murals that give this corner of Tate Britain its name, enveloping the low-ceilinged room so it's a bit like walking into an immersive fairground ride, one designed for flappers and fops.
It really is quite something: you feel almost as though you're part of The Expedition In Pursuit Of Rare Meats. Painstaking restoration has peeled off years' worth of MPs' cigar smoke to reveal their full sylvan beauty. We're transfixed. Which is just as well, because it gives us something to do while being completely overlooked by the staff.
Ah, yes, the service: another remarkable feature of this relaunched curio. We're talking staggering doziness. I'm abandoned and ignored at the front desk behind increasingly enraged tourists. I try to take matters into my own hands by simply walking in, but am escorted straight back out again, despite the fact that a) I've booked and b) the pal is already sitting at our table. There's clearly something totemic about the computer terminal in the centre of the room, because it draws staff like moths to flames. We try to detain a small chap with an improbable coiffure to ask a few questions, but he's jittery with the need to get back to it. Oh computer. Mighty computer.
Then there's the menu: it's ages since I've stared at one for so long without finding something I want to eat. Compiled by the Tate's in-house catering arm in conjunction with a food historian, it's more lesson than indulgence. What, we ask, is Trafalgar trout? "It's, er, trout. With broth. And kale," comes the reply. Way to sell it to us, baby. And kale: how very 1930s.
We resist the blandishments of the trout. But, with the exception of a (tiny) crab starter that features glorious shellfish with delicate, lightly pickled cucumber and the freshness of sorrel, the rest of what we eat is equally austere. Minuscule carrots, again with a touch of acidity, are almost raw and served with mandolined discs of radish. This isn't lunch, it's the 5:2 diet. Sea bream, overcooked, comes with hair-shirty nutmegged spinach. There's pheasant, tough and grey, with an actual porridge of oats and parsley. Some things are history for a reason. Like whooping cough.
But I forgive everything because the wine list– long a whispered, greedy little secret among the capital's bibulous – should be preserved for the nation in the galleries above. This is the most seductive of the extraordinary things: 50-odd pages, curated – and I think it's fair to use that maligned word here – by Hamish Anderson, the Tate's wine adviser. There are suggested wine pairings with each course; a good way, we reckon, to give it a workout without resorting to stratospheric sums.
Trying to get information from the sommelier about the pairings is tricky. ("What comes with the bream?" "Roast potatoes.") But everything he brings is a joy, ranging from merely delicious – an almost savoury Passagem from Portugal – to revelatory: Pfaffl Wein 2, a supple Austrian pinot noir full of frisky cherry fruit. With a Sussex pond pudding (half a lemon baked in a suet crust, so sticky juice pools out when you cut into it), we're given a healthy swig of Christmas cake-y Rutherglen muscat. There are rumours of under-the-counter swag, but trying to access that would probably have brought the sommelier out in hives. The bill for this boozy wallow is much lighter than I expect. File under London: scenes you seldom see.
I can think of little nicer than sinking into a table here at lunchtime to pay homage to that wine list, pouring out into the Millbank dusk, properly toasted, several hours later. National treasure? Even with the Keystone coppery of the staff and eccentricity of the menu, I'd say so. And the gallery's not bad, either.
• Rex Whistler Restaurant, Tate Britain, Millbank, London SW1, 020-7887 8825. Open lunch, all week, noon-3pm; dinner, first Fri of every other month, 6-9.30pm. Three-course lunch, £27 a head, plus drinks and service.
Food 5/10
Atmosphere 8/10
Value for money 8/10 (mostly for the wine)
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