If your only experience of sushi is a supermarket selection box, your miso-ing out says Catherine, as she takes a lesson at sushi school.

Brightly-coloured plates of exotic food whir past me along a conveyor belt, like delicious planets in orbit. Inches from my nose is a vibrant orange salmon that’s the size of a small child. And I’m wearing greased-up rubber gloves and massaging rice into a seaweed sheet.

But this isn’t some kind of weird dream. I’m at YO! Sushi sushi school, learning the difference between nori and nigiri, and how to master maki.

Many people think sushi means’fish’ but, our teachers for the evening tell us, it means cold rice that’s dressed with vinegar and shaped. It can be garnished with fish or vegetables.

YO! Sushi use veggie ingredients as well as fish both in the restaurant and in the sushi school. They’re keen to extol the virtues of ingredients such as avocado, cucumber, tamago (a layered Japanese omelette) and inari (a seasoned, fried tofu bean pouch), and have even introduced Green Wednesdays until September, where you can try 20 of their vegan and veggie dishes for £2.30 per plate.

I have to confess that when it comes to sushi, I’m a novice, having mainly eaten supermarket selections as a speedy and tasty lunch.

But thanks to our sushi-savvy gurus dishing out morsels of information during the two-hour lesson, I’m soon up to speed.

We learned about the origins of sushi – in the 1300s fish was wrapped and salted with rice to preserve it – and about Giro, the best sushi restaurant in Japan. We discover how nori is made, and learn that salmon is only really served as sushi in the West – in Japan you’re more likely to have yellowfin tuna. We also found out that some sushi chefs spend five years just learning how to perfect the rice!

Thankfully, our rice was already prepared. After dipping our fingers in vegetable oil, we gently pressed it onto a sheet of nori (pressed seaweed which you can buy from Asian food shops and bigger supermarkets).

It needs to be perfect. Too much and it’ll bulge out, too little and your sushi roll will look anaemic. We add a baton of cucumber, sprinkle on sesame seeds then carefully roll it within our bamboo mat before chopping the sausage shape into neat pinwheels. Cucumber Maki: Done

Next up, is the yasi iso roll. This time, we leave a one-inch rim of rice hanging down from the nori sheet. We layer inaro, which has the texture of fried egg but tastes sweet like treacle, with spiralised carrot, avocado, lettuce and tamago. We then roll it with the rice-side facing out.

A few extra goes within the bamboo mat helps smooth out the join. Then, after sprinkling shichimi powder, a Japanese chilli spice blend that’s so delicious I’m now addicted, it’s cut into disks.

My rolls look so pretty, like something you’d see down a kaleidoscope. Freckled with chilli powder, there’s a rainbow of colours at their centre. They’re a riot of flavour and texture – sweet tamago, creamy avocado, slightly vinegary dente rice.

After that, we’re on a roll (sorry!), shaping rice, adding a blob of wasabi, then topping with salmon to create a nigiri; making a California hand roll by wrapping vegetables into a neat seaweed cone and topping with spicy mayonnaise.

If you take part in the sushi masterclass, you can chomp on your creations as you go along. It’s nice to have a drinks list that bucks the norm and we washed our sushi down with potent but palate-cleansing sake, ramune soda (Japan’s oldest and most popular drink, a lemonade that tastes a bit like bubblegum) and a supersized beer.

If you’d prefer to save your sushi to show off to your friends or family, you can take it away in a takeaway box that’s provided. You’re also given a bamboo mat and a booklet with recipes to take home.

I’d highly recommend sushi school as a fun day out for foodies. By the end of our lesson, we’d tried some new ingredients, learnt fresh skills and developed a better appreciation of how varied and delicious sushi could be.

There’ll be no more supermarket sushi for me. After my lesson at sushi school, I’ve graduated onto the good stuff!

For more information on Green Wednesdays and Sushi School visit yosushi.com