Julienne the carrot and put to one side. Slice the cucumber into ½-cm thick slices and put to one side. Place the Sichuan peppercorns in a saucepan with 1 Tablespoon of the vegetable oil and turn the heat to medium. Keep stirring the pepper as the oil heats up, and at the point when they become aromatic, slowly add the vinegar and mirin mixed with 300 ml warm water, and 1 teaspoon fine salt. Bring to the boil and cook for 2 minutes. Add the carrots to the pan and bring back to the boil then take off the heat and add the cucumber. Give it a gentle stir, put a lid on and leave to go cold, then decant into a clean jar, seal well and store in the fridge. Best left for at least a day before using.
Make the mousse by placing the diced fish and tofu in a food processor and blitz for 15 seconds, scraping the sides halfway through. Scrape the sides again then add the shichimi spice, spring onions and some salt and blitz for another 5 seconds. Tip the mousse into a bowl and mix in the gari and crab meat. Place in the fridge and leave for at least an hour to firm up. Divide the mixture into 12 and roll each one in the breadcrumbs, gently pressing the crumbs onto the mousse’s surface. Place on a plate and put back in the fridge.
Set up a deep-fryer with 5 cm of oil in it heated to 180°C. Lower several fritters at a time into the hot oil from a slotted spoon and cook as many as will comfortably fit in the pan until golden. Remove and place on kitchen paper to drain.