I say sushi, you think raw fish. This, perhaps, is the reason why the Japanese delicacy, unlike the noodle or the stir-fry, has not become a staple of British home cooking. But all that is about to change – at least if Yuki Gomi, 37, a Japanese sushi chef living in London, has anything to do with it. “In Japan, going to a sushi restaurant costs hundreds of pounds and is a real treat,” she says when we meet at her flat in Crystal Palace, south-east London. “But Japanese people make it at home all the time, usually without raw fish.” When a Japanese family goes for a picnic, sushi will always make an appearance – but smoked fish will also be used, which is less likely to spoil (salmon and mackerel are favourites). Children take sushi to school in their lunch boxes, made with tinned tuna. There are vegetarian options, including tamagoyaki, grilled egg sushi. “If you want to go the whole way and use raw fish,” says Gomi, “there are safe ways of doing it. If you have the confidence, you can make friends with a local fishmonger and get him to promise you that the fish can be eaten raw.

But the easiest way is to buy sushi-grade fish on the internet.” She recommends Kazari, which will deliver guaranteed sushi-grade fish to your door. Sushi is easy to make, extremely healthy and highly portable. It is also flexible; jiro dreams of sushi portuguesthere are, Gomi says, “no rules”, and new combinations of fish or vegetables are waiting to be discovered. juego hacer sushi icarlyAnd when it is home-made, sushi can also be an impressive addition to a party.jiro dreams of sushi glasgow “It is simple, so long as you are precise,” she says. sushi grade fish hamilton ontario

“Architects and surgeons make the best sushi.” Yuki Gomi encourages home cooks to find sushi-grade fish online (HEATHCLIFF O'MALLEY) Before thinking about the fish, however, it is important to get the rice right. It must be Japanese – which refers to the species rather than the country of origin – because it is high in starch, which makes it stickier than other varieties. togo sushi palm desertTechniques for cooking perfect rice are closely guarded secrets for many Japanese chefs. sushi delivery london n4Gomi, however, being “of a younger generation”, is happy to share her method, which she learnt from the masters (see right). When the rice is ready, the creative part begins. First, Gomi demonstrates how to make temari. “When you go to a restaurant, you’ll probably have nigiri, rectangular slabs of rice with salmon or tuna on top,” she says.

“Shaping the rice like that takes years of practice. Temari is the traditional home-made version, which is a lot easier.” Cutting a fillet of raw salmon is an art in itself (she points out that smoked salmon, mackerel or kipper can be substituted). Gomi uses a traditional yanagi-ba sushi knife, which is flat on one side and very thin; The trick, she says, is to hold your breath and make the cut in one movement, as if you are playing a violin. When the fish is sliced, she covers her left hand with cling film – an improvement on the traditional muslin – and lies a sliver of fish in the centre. A bolus of rice is placed on top, then the cling film is closed around it and twisted to make a tight sphere. When this is unwrapped, a ball-shaped piece of sushi is revealed, which can be garnished with sesame seeds, a sprig of parsley, or fish roe (tobiko). Next, she makes the “inside-out roll”, also known as the “California roll”. For centuries, Japanese sushi roll had the nori (seaweed paper) on the outside.

When it was introduced to California, however, the local chefs preferred to roll the sushi inside out so that the rice was on the outside. This was later exported back to Japan. She places a sheet of nori – she recommends the type produced by Clearspring (clearspring.co.uk) – on a board and covers it with a layer of rice. The rice is sprinkled with roe or sesame seeds, turned upside down onto a bamboo mat (available from Tesco, £1.99) and covered with cling film, before arranging the salmon and avocado, rolling, and slicing with a light sawing motion. Lastly, Gomi introduces the temaki sushi, which she says is a great informal party option. In a large bowl, she mixes scallops, flying fish roe, mayonnaise and avocado. This, together with a bowl of sushi rice and another of sliced vegetables, is placed on the table with a stack of nori. Guests add the filling to the nori and roll it into a cone for instant, do-it-yourself sushi. “When I was a child and my mother said we were going to have sushi, I was always filled with excitement,” says Gomi.

“I want to bring some of that excitement to Britain.” ’Sushi at Home’, by Yuki Gomi, is out now (Fig Tree; £18.99)You speak, we listen. That is the way it works at Word of Mouth. Consequently, after the enthusiastic response to our recent supermarket sandwich taste test (as one contributor, Edinburgh17, put it: "Forget gadget porn. THIS is consumer journalism I can get into"), we have decided to do a regular supermarket sweep, browsing the aisles monthly to put one of Britain's lunchtime favourites to the test. First up, supermarket sushi, a once glamorous product that is now a staple on the high street. Purists will scoff at this packaged product prepared in factories, which cannot by law include raw fish. It is like a rolling insult to Japan. The labyrinthine ecological concerns around the use of, say, farmed salmon and Thai prawns in supermarket sushi (even if many retailers now use line- and pole-caught tuna) is another reason why many people steer clear. However, the fact remains that for the weight-watching office worker, sushi – according to Seafish, a market worth £64m and growing at 14% annually – is one of the few readily available options out there.

Little wonder it is on a (maki) roll. But which of our supermarkets take sushi seriously? Tesco is chasing hard, but can it compete on flavour with the slicker market-leaders, M&S and Waitrose? Onwards, to the check-out chow down ... Boots plays pretty fast and loose with the concept of sushi. It is home to both "street sushi" (BLT sushi, anyone?), and, in this pack, smoked salmon "nigiri", which, rather than a block of rice draped with fish, is (admittedly, properly glutinous, sticky) rice into which the fish has been chopped and mixed, pretty meanly. Both it and the red pepper version taste blandly sweet. The cucumber maki rolls are almost devoid of all flavour and cry out for more than the rather caramely, low-salt soy sauce that is included (where is the wasabi or pickled ginger that is standard elsewhere?). The smoked salmon in the maki is reasonably meaty, albeit with a curiously citric edge. As for duck maki, what's that all about? It murmurs reassuringly in your ear: pole- and line-caught tuna;

cured Lochmuir™ salmon (that sounds good, right?); pickled ginger and real Japanese wasabi. It is eye-catching, too. Trouble is, with the exception of the sesame-seed coated California tuna roll, it tastes – even that fabled Lochmuir™ salmon – of very little. This set is all about the condiments: that clean, fiery wasabi (Kinjirushi brand, used by several supermarkets it transpires) and the well-balanced soy. Pickled ginger is supposed to be a palate-cleanser, but chuck that on too, and you can turn the prawn nigiri into a pretty explosive mouthful. But, basically, you are building flavour in retrospectively. Only £2, yet this pack includes Japanese wasabi and a tangy, umami-rich, naturally brewed soy. The prawn (dry, fibrous, flobby) nigiri on overly dense rice is a washout. However, the black-sesame-coated sweet chilli prawn and red pepper California roll delivers reasonably interesting, not overly sweet flavours, as does the teriyaki tuna and cucumber one. Assorted little vegetable hosomaki (red cabbage, carrot and pickled ginger etc) taste predominantly of the nori seaweed wrap, but, again, a bit of diligent work with those condiments will jazz up that rice.

Factoring in the price … With the exception of a deeply unpleasant smoked salmon and cream cheese (yes, cream cheese and rice!) futomaki, there isn't anything too crazy going on in this, "variety sushi". In fact, I would hazard a guess that Sainsbury's shares a supplier with the Co-Op, as this set features the same condiments (yay!), similarly woeful nigiri (sad prawn; compacted, drying rice), and teriyaki tuna and sweet chilli prawn Californian rolls that, while not identical, are close cousins of the Co-Op versions. Sainsbury's is marked down for the cream cheese and for including not one, but two of those naff nigiri. Note: Sainsburys tuna and prawns come from MSC-certified fisheries. Serious deja vu now, as I open another Kinjirushi wasabi, another Shoda naturally brewed soy sauce. Overly keen to look authentic, Tesco even includes chopsticks when everybody knows (no, I didn't either), that sushi is finger food. Such kowtowing to supposed tradition is ironic, given that the California rolls – char siu chicken, hoisin duck, sweet chilli and ginger prawn – go disastrously off-piste.

In fairness, they do taste of something, but in a cheap, clumsy way, where everything is far too sweet and the flavours clang about. Sweet chilli chicken hosomaki is as bad an idea as it sounds, the red pepper nigiri is almost inedible. The smoked salmon is the only pleasant component. Waitrose sells a lot of different sushi sets from its persuasively named supplier, Taiko Foods, at up to £6-a-pop. It clearly fancies itself as the UK's premium supermarket sushi dealership and, on this evidence, with good reason. Poached salmon, sesame-coated California rolls finally deliver some of the subtle but true and clean, complementary flavours that you expect from sushi. You don't immediately reach for the imported, Japanese condiments (the wasabi is a real rip-snorter). Mini vegetable and ginger nigiri have a distinctive pep and zing. The shrimp maki are overwhelmed by the nori, but it is a sound platform for the stridently but smoothly smoked salmon. • Follow Tony Naylor on Twitter: @naylor_tony