Sushi Tetsu, London – Restaurant Review

I could save you some time and just say that if you're after the best sushi experience in London then go to Sushi Tetsu and be done with it. But where would be the fun in that? This tiny restaurant in an obscure Clerkenwell alleyway is serving up some of the most authentic sushi I've had outside of Japan.

Sushi Tetsu quietly opened in June 2012 and is the creation of Toru Takahashi and his wife Harumi. In just a couple of short months the restaurant has received near reverent praise from many quarters. Such is the minuscule size of Sushi Tetsu (just seven stools surround its blonde wooden counter) that many dare not even speak its name for fear that the restaurant will be fully booked in perpetuity. But it would be a shame to keep such a wonderful place a closely guarded secret. If you love the precision, theatre and ritual of authentic Japanese sushi then a pilgrimage to Sushi Tetsu is a must.

Toru Takahashi himself hails from the Yamagata prefecture of Japan, an area known for its natural beauty – a feature that seems to be reflected in the food that Toru-san serves. After spending some time training as a sushi chef in Kobe, Takahashi moved to London where he spent seven years working at Nobu. Turning his back on the famous restaurant's modern Japanese dishes such as yellowtail sashimi with jalapeño and its iconic black cod with miso, Toru-san and his wife decided to create a simpler restaurant that is more reflective of the traditional minimalist sushi bars you'd find in Japan.

And it's certainly been a labour of love for the couple. With so few seats, the restaurant is always busy for its lunch and dinner services. And what's even more incredible is that Takahashi and his wife are currently the only employees – Toru skilfully wielding his knife behind the counter, while Harumi is the ever-graceful hostess. In fact, on finishing our dinner sometime around midnight, Toru remarked that they'd be washing the dishes later as well as the prep for the next day, probably finishing sometime in the early morning. It's a gruelling workload for the couple, and Toru's even been known to set up a camp bed in the kitchen! I hope for their sakes they get some help quick and allow Takahashi to focus on what he clearly does best, which is dishing up the most sublime sushi I've had in London.

There is a menu at Sushi Tetsu, but you're best advised to leave yourself in the capable hands of the itamae and opt for the omakase menu. But be warned, the bill can add up fairly quickly. Especially if you, like me, decide that one or two pieces of the heavenly o-toro tuna is simply not enough. On both my recent visits to the restaurant the bill came to around £150 per person, but there may have been more than a bit of daiginjo sake and cold beer involved too.

We begin by watching as Toru-san elegantly prepares some impeccable cuts of sashimi: sweet scallop slicked with a mystery soy-based sauce is lightly singed with a blowtorch; soft pieces of chu-toro (medium-fatty tuna); gleaming ama ebi (sweet prawns); a quick flash of the knife creates vibrant slices of hamachi (yellowtail); and suzuki (sea bass) is coated with a refreshing ponzu sauce.

On another occasion we were again served chu-toro, yet this time we watched as Toru-san carved wafer thin slices of hirame (halibut) and arranged them in a precise fan shape, the tip of each end folded over to give it some height. The hirame had a wonderful bite to it and was dressed with the same ponzu sauce as before. Toru-san explained that he makes the sauce himself from sun-dried kombu, bitter mirin, soy sauce, yuzu, and bonito flakes. It was much lighter and more fragrant than ponzu sauces I've had before, and I could easily have drunk it on its own. My only niggle, though, was the mass-produced wasabi paste on the side. It would have been a really nice touch to use freshly grated wasabi, which has an infinitely better taste.

A damp bamboo leaf is placed in front of us, which acts as our plate for the procession of nigiri sushi that is to follow, and a small, constantly replenished mound of gari (pickled ginger) is placed on it. With a cold glass of Asahi beer in hand, we watch as Toru-san deftly crafts each piece of sushi in front of us.

Chopsticks are available, but you're encouraged to eat your nigiri in the traditional way with your fingers; a folded wet napkin is handily provided for you to clean your hands. A soy sauce dish is also provided, although this proved redundant for the nigiri sushi as they come perfectly seasoned after being brushed with soy sauce.

We began with tai (sea bream), which had a sliver of shiso leaf tucked underneath the fish. The effect was to give the whole thing a zesty peppery freshness. The first thing I noticed though was the rice. Always the mark of good sushi, the rice Toru-san makes is served at body temperature and its seasoning is well-balanced, perhaps being a tiny bit sweeter than is typical. It's perfectly formed too, having just the right stickiness and density.

Next was sake (salmon), which had a surprisingly denser texture to it than I was expecting. I probably eat salmon three times a week here in Norway, but this example was very special indeed.

This was followed by ebi (prawn), which had been boiled and lightly grilled on the underside. I usually find ebi to be the least interesting kind of nigiri, but that's probably because I've never had one as fastidiously prepared as this.

Akami (lean tuna) seemed just as succulent as its more revered fatty sibling, o-toro, but had a subtler and more complex flavour.

This was followed by o-toro, one of the highlights of the meal. And such was our love for the fatty cut of tuna belly we ended up ordering a few more pieces later in the meal, much to our credit cards' chagrin.

We watched as Toru-san picked a cut of o-toro from a wooden box containing various pieces of tuna gleaming like rubies in a jewellery box. He then sliced the fish and lightly scored each piece to increase its surface area, before brushing it with soy sauce and quickly grilling with a blowtorch, giving the o-toro a gentle hint of smokiness and released some of the fatty oils in the fish.

This was nothing short of stunning! 'Melt-in-the-mouth' is such an overused phrase, but I can't think of anything more appropriate to describe the way the tuna just seemed to disappear on the tongue.

Even better, though, was o-toro served, at our request, without being grilled. I preferred the perfect simplicity of this preparation and the absence of any char-grilling let the pure flavour of the tuna shine through.

Aji (horse mackerel) was spankingly fresh and was served with a few curls of spring onion underneath, all the better to cut through the oily richness of the fish. 

Mategai (razor clam) was sweet and tender and was served lightly flame grilled with a few drops of sudachi squeezed over the top, giving it a wonderful citrus freshness.

Next, a strip of cucumber, instead of the traditional nori, was skilfully carved to create a gunkan-maki of uni. Unfortunately the sea urchin – sourced from Canada – was a little past its prime and had a bitter metallic taste to it. I've definitely had better quality uni before and this was to be the one fault in an otherwise impeccable meal.

Matsubagani (snow crab) gunkan-maki was made from delicate flakes of sweet snow crab meat.

An o-toro hand roll was made by painstakingly scraping a piece of the fatty tuna with a knife to mince the flesh and remove any small sinews, resulting in a texture that could easily have been spread with a knife.

Ika (squid) was precisely scored with a knife and then wrapped with a strip of nori. It still retained a little bite to it with absolutely no hint of rubberiness.

Tako (octopus) had been massaged by Toru-san to tenderise it (cue flashbacks to that delightful octopus massaging scene in 'Jiro Dreams of Sushi') and was served with a little umeboshi (pickled plums) giving a tangy acidic balance to the sweet tender octopus.

Ikura (salmon roe) gunkan-maki was full of gleaming pearls of salmon roe – I just love the way they burst in the mouth. A couple of slivers of sudachi zest gave a fresh burst of citrus to balance the oiliness of the roe.

Next was a dish not for the faint-hearted. My dining companion was speaking with Toru-san about the surprising joys of eating fish guts when he used to live in Japan. With a little glint in his eye Toru-san placed a bowl in front of us containing a mysterious, as yet unidentified, morsel. It had a musty pungent smell, not unlike a really ripe cheese. It had a chewy texture with a slight creaminess to it and it tasted much milder than it smelt, with a complex savoury umami taste. It was really rather delicious.

This was in fact ika no shiokara, or fermented squid guts. Toru-san occasionally makes it himself by salting raw squid viscera and letting it ferment in a closed container.

I live in Norway and here there is a strong tradition of fermenting fish, so the flavour of the shiokara was not alien to me. In fact it was a little bit like a milder, but much tastier, version of the infamous Norwegian rakfisk, which is fermented for much longer. It's an acquired taste, but I can easily see its complex savouriness becoming quite addictive.

This was followed by something more familiar. Tara (cod) had been marinated in kombu and was served with (I think) an oil-dipped shiso leaf underneath. Following the richness of the shiokara, this was a light and fragrant bite.

We ended our meal with a piece of tamagoyaki (grilled egg). This is a real test of skill for an itamae, and Toru-san's example was simply stunning. It's made with beaten egg to which (among other things I'm sure) sugar and prawn paste were added. It had such a light cake-like texture with a wonderful sweet/savoury taste. In fact, for all but the most hardened of sugar addicts, it was probably sweet enough to pass as a dessert proper and was a fantastic way to end the meal.

It's difficult to sum up a meal at Sushi Tetsu. The tiny dining room with just seven stools surrounding the chef lends the place a real intimacy. Toru Takahashi and his wife Harumi play the role of extremely gracious hosts and the small room quickly fills with laughter and playful banter.

But the real joy is the food, which is made with such precision and elegance by Toru-san and the almost balletic movements of his razor sharp knife. It really is some of the best sushi I've had outside of Japan, and for a few moments during your meal you'll feel transported back to some tiny Ginza sushi bar. But forget the comparisons with Japan, we're in London after all, and Sushi Tetsu is quite simply one of the best restaurants in town. So go and make a reservation, you'll love it.

Food:          9 / 10
Service:      9 / 10
Ambiance:  9 / 10