Kikuchi, Fitzrovia

There's an argument - a strong argument - that Japanese cuisine is the pinnacle of human achievement in gastronomy. Japan is a country that has, by most measures, devoted itself to the cause of good eating and drinking to a degree hardly matched anywhere on the planet; a nation of producers, chefs and diners of exquisite taste and infinite capacity for skill and invention, where you can eat extraordinarily well from the very cheapest noodle shops to the highest of high-end kaiseki multi-course tasting menus. The French, the Spanish, and the Italians may fight their corners pretty well, but deep down I suspect even they know the truth - the Japanese have spent thousands of years quietly dedicated to eating as well as they possibly can, and there's nobody else can touch them.

Outside of the motherland itself, though, Japan often struggles to find decent ambassadors for its food. "Airport sushi" has become shorthand for disgusting overpriced plastic crap served to captive audiences, although it's the supermarkets we have more specifically to blame for diabolical things such as cooked tuna in a California roll. But actually, there are just as many pitfalls in the mid-ranges, certainly in London anyway; it's a brave soul indeed who would wander into a sushi joint in Covent Garden without doing their research, or indeed any ramen place outside of the Big Three of Kanada-Ya, Shoryu or Tonkotsu.

So a good Japanese restaurant in London is to be praised and cherished, and enjoyed by as many people as possible. Kikuchi, round the back of Tottenham Court Road, is one such place - our very own slice of Tokyo serving some of London's best sushi, an experience so profoundly authentic, from service to décor to food, that if it weren't for the fact the toilets didn't have a panel of flashing buttons on them and the bill came in pounds sterling, you really could believe you were 6,000 miles away.

Our "omakase" (surprise tasting) menu began with mackerel-wrapped cucumber and seaweed, good fresh fish and a pretty presentation, to be dipped in to an umami-rich mustard and miso sauce. I can't honestly say a bit of boiled broccoli added much to proceedings, but on the other hand it did very much feel like the kind of thing I was given on my trip to Japan, so I'll let it slide.

Thin-sliced turbot with ponzu sauce was a fantastic showcase for a premium bit of seafood. Often with a very citrussy dressing some more underpowered types of fish can be lost, but this turbot had a lovely meaty flavour and a good strong bite. A clump of interesting mustard leaves of some kind it arrived with packed a palate-cleansing punch, as well.

A trio of tempura items each had something to recommend it. On the left, a "sweet prawn" (from Canada I think), in the middle a clever sandwich of sea urchin, and on the right the one that had us both grinning, a morsel of sea bass hiding a fantastic sharp plum sauce.

Another tempura dish, this time eel with grated yam draped over the top. I don't know whether it was because the yam looked so much like melted mozzarella that I was a bit disappointed with its decidedly non-cheeselike flavour, or whether I just don't like yam full stop, but this one didn't do much for me. The eel itself was nice enough, but there wasn't enough balance overall and I found it a bit carb-heavy and dense. On the other hand, it still felt incredibly authentic, like one of the many dishes I was asked to eat in Japan and didn't like there, either. House ginger pickles were great, though.

The introduction dishes done, we were now onto the main event, a succession of nigiri involving some top-quality seafood. There's probably not much point in going into exhaustive detail about each one, so I'll just leave the photos (in order, horse mackerel, fatty tuna, sea bream, jumbo prawn, squid, tuna marinated in soy, sea urchin, very fatty tuna and egg tart). However, special mention as always has to be made of both the otoro (fatty tuna, think a fishy version of wagyu beef, heavily marbled and packed full of flavour) and a first for me, very fatty tuna (hotoro, as far as I can gather from Wikipedia), even lighter with fat and even more intensely flavoured.

Sushi like this is why you'd come to a restaurant like Kikuchi, in fact food this good is why one eats out at all. Reaching back into the depths of my memory, it's possible I have had nigiri as good as this before, perhaps at Tetsu in Clerkenwell, or the odd piece at Roka. But no matter how prepared you are, no matter how blasé you've allowed yourself to become about fine dining in London, it can still never be anything but a shock - a glorious, heavenly shock - to be handed a slice of fine seafood draped over body-temperature, fluffy rice, and just sit back and let all the incredible flavours and textures play out. These tiny morsels of food are the final endgame of a life's work mastering the art of sushi, with a thousand years of food culture to draw from. Each one a mini masterpiece.

Of course, fine art comes at a price. The omakase at Kikuchi clocks in at £120 a head, with a flight of sake (not matched to the courses as such, just three premium small glasses to work at during your meal) an extra £50 or so. But for that you get what is undoubtedly one of the most accomplished and enjoyable sushi experiences in the country. The attention to detail is startling - from a giant prawns head enlivening a bowl of miso, to a digestif of fantastic yuzu liqueur which I could recommend thoroughly if I knew what the hell it was called. Still, there's a picture of the bottle.

London may still not be able to boast the abundance of sushi riches that certain parts of the USA or Australia are blessed with. Perhaps we never will. But Kikuchi (and Tetsu, and probably Araki although not being a gazillionaire I doubt I'll ever go) is proof that producing a truly top-end dining experience is, in common with any type of restaurant, just a matter of getting a group of talented people together in a room and letting them do their thing. The team at this unassuming little restaurant round the back of Tottenham Court Road ought to be very proud of what they've achieved, and I am very grateful indeed to have been allowed to experience it.

9/10

My meal at Kikuchi was comped.