Cubé, restaurant review: Small but serious sushi bar

We're eating so much more sushi these days — except most of it scarcely deserves the name. The Guardian ran an impolitic article a couple of months ago in which two serious sushi chefs, Yuya Kikuchi, of tiny Soho joint Jugemu, and Teruya Noriyoshi, head sushi chef at Nobu, were invited to try out chain and supermarket sushi boxes. They struggled to find any way of overcoming their natural courtesy enough to tell the obvious truth. Sainsbury’s, which sells 90,000 sushi packs a week, came off worst — but Waitrose and Marks & Spencer fared little better.

Any sushi that has been sitting around in a chill cabinet has little in common with sushi skilfully made by hand, moments before eating, where the fish is fresh and the rice still warm, except perhaps as a coarse parody. Japanese chefs may insist that it takes a year to learn how to cook rice properly and recoil from wrongly cut fish but you don’t need to be very accomplished to produce sushi at home that, however technically incorrect, is more delicious than the supermarket horrors.

Eventually, contemplating what the British are eating in the name of takeaway sushi, chef Noriyoshi was stymied by good manners: “I can’t say any more bad comments!” Equally understated, chef Kikuchi looked on the bright side, to a better future: “If people start to eat it more, and learn more about sushi, they will understand what it should really be like.”

Meanwhile, London at least has, by the month, more and more places where good sushi can be eaten, at varying price levels, including the Japan Centre’s new flagship store at 35 Panton Street, which opened last week. It boasts a large and already busy basement food hall where you can take your modestly priced food to communal tables before browsing the tempting specialist Japanese groceries — a whole bay of different misos, for example, or even, if you look carefully, a tiny bottle of precious yuzu juice (£10.68 for 70ml).

And here’s Cubé, a new launch in Blenheim Street, part of that slightly unpropitious dogleg between Oxford Street and Bond Street, which the restaurant hopes nonetheless to be considered Mayfair. On Monday night there were a few of those international prannets illegally displaying their futile supercars and rorty superbikes on this corner, so perhaps it’s high-end after all, despite being only a few steps from the grot of Oxford Street?

At any rate, Cubé is a serious place. The chef, Osamu Mizuno, was previously at Nobu and Sake no Hana, while the manager, Mayumi Nunn, comes from Kanada-Ya and Eat Tokyo.

At the top level there’s a pre-bookable “omakase” (“I’ll leave it up to you”) menu for up to five diners, sitting at the sushi counter, with the chef choosing what to make for you before your eyes, at £75 a head.

At lunch, though, the offer is much simpler: set meals, including different bento boxes at £20-odd. Mixing together the Cubé and “weekly” selections last Friday, we got some tempura, including prawns as well as vegetables, with a bland sauce, some slices of good sashimi (salmon, tuna, sea-bream), fair rather than ravishing miso soup, some broccoli and sugar-snap peas served cold, small slices of rare cooked duck with home-made pickles, a generous serving of lightly grilled teriyaki salmon, a spinachy salad dressed with sesame and garlic, some cubes of silky beancurd in a light crust — all straightforward, served in carefully placed separate dishes, enjoyable for a healthy lunch.

A little serving of tiny, soft but still chewy beef pieces, braised in very sweet miso, with burdock, appealed less — often in Japanese cooking textures are as challenging to Western palates as tastes. A fresh fruit salad, for example, came with a springy plum wine gelée that only those with a jellyfied childhood could love.

Perhaps we should have looked beyond the bento boxes? To hitsumabushi (£19.90), for example, Nagoya’s refinement of the popular summer dish, unadon, in which chopped, soy-flavoured eel is served over rice with dashi broth? Or even the entirely non-traditional foie gras don (£22.90) — for it is Cubé’s USP to offer, alongside a full sushi and sashimi menu, some more Western-inflected luxuries.

Hence the “tapas” approach in the evening and the concentration on wine, rather than sake, including an ambitious list of special bottles from the “owner’s cellar”, priced in the hundreds — although a clean, organic Chablis is £34 a bottle, £8.50 a glass. Cubé doesn’t want to be your straight up izakaya (Kiri is directly opposite — not to mention a busy YO! Sushi just round the corner).

David Sexton's week in food

Walnuts are the only superfood I believe in and, for a little dinner at home on Saturday I made a starter of raddichio, wet walnut and gorgonzola salad, only to discover I had bought a dolce, not piccante, version of the cheese. Doh!

At Ally Pally farmers’ market on Sunday we recruited ourselves with pretty good salt and pepper squid and chips from #Fish London. Followed by a beer at the palace.

Baby Laurie has progressed to solids but the squeezy sachets of purée you can buy are bizarre cocktails (squash, carrot, apples and prunes) all very sweet to the taste. Alarmingly, in First Bite, Bee Wilson says the “flavour window” when babies will try anything, even greens, is only from four to seven months.

Catering arrangements at the Evening Standard offices continue to confound. Here’s that avocado toast, with chorizo and pepper, to cheer up our Monday mornings. Believe me now?

Partridges are back: roasted for 20 minutes at a high temperature with lots of pancetta, served with Florence Knight’s sloppy bay and onion-infused milk polenta, with some truffle oil poured over. A nice Nebbiolo helps. Autumn.

From this tapas menu, aburi salmon carpaccio (£8.90) was delectable — half a dozen very thinly sliced pieces of salmon, just brushed with a blowtorch to melt a little of the fish’s fat, without cooking it at all, before it is dressed with some lemon juice and a precisely applied dab of fresh wasabi, so mild and aromatic it makes the crude heat of the powdered version seem gross.

Similarly, agedashi tofu with watercress and truffles (£5.90) was delightful, the broth much enhanced in its umami yumminess by a powerful truffle aroma, offsetting the blandness of the beancurd — whereas pouring truffle oil over edamame beans still in their inedible pods (£4.50) seemed pointless: better just to dunk them in chilli, shallot or plain salt.

Simple, Japanese deep-fried dishes were good: karaage chicken sticks (£6.90), for example, and mackerel tatsuta age (crisply coated in potato starch, not flour). Other less common Japanese specialities available here are, I conclude, acquired tastes, probably beyond my acquiring. Mentai renkon cheese, currently fashionable, was a shocker, slices of unappealing lotus root, any cheese dominated by the super-spicy fish roe; capelin yuzu nanban proved a cold, strongly pickled small fish, teasingly close to rancid.

Never mind. It would, with conservative ordering for conservative eaters, be very easy to have a fine time here, especially if you’re not counting the cost (tuna sashimi comes in three grades, akami, chu toro and the ultra-unctuous otoro, rising from £8 to £11 for three pieces).

Service is graceful and the design minimal, not to say fanatically woody, great sheets of raw Douglas fir covering all the walls, and used too for the tables and benches, so that it feels a bit like being inside a lavishly expanded packing case or a sauna that has yet to be used. Cubéd, perhaps. Although seating only 24 diners, plus another 12 in a basement bar, it is not yet much discovered: for now, a most soothing venue for a drink and a plate.

4 Blenheim Street, W1 (020 7165 9506, cubemayfair.com, info@cubemayfair.com). Mon-Sat, noon-2.30pm and 6pm-10.30pm. From £50 for lunch for two, to the limit for à la carte in the evening.