This may just be the most reprehensibly middle-class thing I've ever done. I'm texting my nanny to make arrangements to get my son to a sushi-making class in Soho. What next? Bikram yoga sessions with my mother? A Kabbalah initiation with the man who fixes my car? Please, just shoot me now.
In my defence, I signed up for the class in an attempt to broaden the horizons of a seven-year-old for whom eating something that isn't pizza or pasta is really pushing the envelope. Sushi is just about the only thing David likes to eat that doesn't come with tomato ketchup, a taste born from occasional visits to those conveyor belt restaurants, where the rotation of the colour-coded plates seems to hypnotise even the most unadventurous young diner into wolfing down quantities of raw fish. Capitalising on that enthusiasm, I volunteered us as guinea pigs for a new sushi class for parents and children, organised by So Restaurant after similar classes for adults proved popular.
David comes after school with his friend Daniel, who hasn't eaten sushi before but is equally keen to miss swimming. Only as we are standing outside So, looking in at the cool, minimalist interior, does the reality of what we're about to do sink in, and with it, recognition that the codified formality of Japanese culture is not something that two boisterous seven-year-olds are necessarily going to grasp instinctively. "Our teacher will be a great master," I intone, like the voiceover at the beginning of Kung Fu. "He will have trained for many years. You must show him respect, and listen when he is talking to you." And don't throw food or, please God, make farting noises with your wet hands.
I hustle them past the sushi counter, with its tangle of octopus tentacles, and down into the restaurant's basement dining room, where our work stations are laid out in readiness for us. In my limited experience of cooking with children, this has always been the stumbling block. You set out to make a cake together, and they've already lost interest while you're still rooting around in the back of a cupboard grunting, "I'm sure I had some baking powder in here somewhere." Here, our ingredients are already assembled and prepped. Bamboo rolling mats, dishes bearing balls of sushi rice, slices of salmon and tuna, and adding a less Zen-like touch, damp J Cloths. "Where's the little track that carries the plates around?" asks David. "Is that a film?" wonders Daniel, looking at a glass window through which a chef can be seen chopping in the restaurant's kitchen.
Our teacher for the two-hour session is So's sushi chef Matsuya Tomokazu, or Tomo for short, whose instructions are translated by waitress Koko. It's good manners to bow to your sushi chef when entering a Japanese restaurant, so I attempt a little bow. "Mu-um," hisses David, rigid with embarrassment.
We begin by spreading one of our balls of vinegared rice on to a square of nori, the dried processed seaweed used as a wrapping. The key is to keep your palms damp, using water from a finger bowl, or the rice clings to your hands. As we work our rice, I remember that I am a klutz, and what's more, my son has inherited my klutz gene. Our fellow pupils, a trio of older girls, have made neat little squares; David soon looks like he is wearing elbow-length gloves of sticky rice.
Next we lay down our fillings; weirdly, these are a breadstick and a plasticky orange substance called cheese strings that all right-thinking parents know and shun. "Chef Tomo's original recipe", beams Koko. Chef Tomo obviously doesn't think much of the gastronomic adventurousness of the average British child. David is momentarily fazed by the appearance of this forbidden item. "It's cheese strings!" I encourage. "You know like I always tell you you're not allowed to eat when we see the ads...?"
Still, we press on – literally; turning our nori squares over and rolling them in the damp J Cloths, then pressing them on all four sides using our bamboo mats, to produce a rectangular block – some more rectangular than others. These are sliced into sections by Chef Tomo (he's the only person allowed near the lethally sharp sushi knives) and sprinkled with sesame seeds. And I have to say, with the filaments of cheese strings bursting out in a golden spray, these uramaki, or inside-out rolls, look rather gorgeous. Just don't ask me to eat one.
We move on to temari, or ball sushi, and this time, raw fish is involved. Amazingly, the boys are still concentrating. Even the normally fastidious David, who freaks out if he drops a baked bean on his clothes, is happily applying raw fish to sticky rice and twisting it into a ball in his J Cloth. Who knew J Cloths were such an intrinsic part of sushi-making?
The neat little balls which emerge from our tightly wrapped parcels are probably the simplest way of preparing sushi at home. "Oh, I wish I could eat them now," sighs one of the girls. And we do. Soy sauce is poured, volcanic wasabi is dispensed (to adults only) and chopsticks distributed. The boys snap theirs open and immediately start sword fighting. Tomo tells me that since coming to England, he's starting making his sushi with a firmer consistency, as British people eat their sushi with chopsticks rather than their fingers, as is normal in Japan. Another reason why sushi is the ideal foodstuff for young children.
Our little group thoroughly enjoy eating their creations, and David is still doggedly chomping his way through his platter long after the girls have abandoned their posts. Daniel, on the other hand, has removed the cheese string and bread stick from the centre of each of his uramaki and eaten it, leaving perfect rings of rice and nori, like the Olympic symbol. It's the idea of eating seaweed that's putting him off. "It's meant to make your hair nice and shiny and ... black," encourages Koko, tailing off as she looks around at her class of flaxen haired kids.
"What was the best part of the day?" I ask the girls. "Learning something new," replies Evie. The boys, meanwhile, are pressing around Koko, clamouring for the giveaway she's dispensing. It's packets of cheese strings.
Family sushi classes today & next Saturday, 3.30-5.30pm, £60 a head inc. wine; £35, children over 6. firstname.lastname@example.org So Restaurant, 3-4 Warwick St, London W1 (020-7292 0767)