dashi vinegar

Combine the vinegar, katsuobushi and kombu in a container and leave to infuse.
Strain before use.

tare

Whisk or gently warm together the sake, burnt-off mirin, sugar, dashi powder and dashi soy until the sugar has fully dissolved.
Cool and store for seasoning the tuna.

rice cutting

Whisk the dashi vinegar, sugar, salt and dashi powder together, making sure the solids are fully dissolved.
Bag in 150g portions and vacuum-seal on a full seal (ready-to-eat).
Keep in the fridge.

sushi rice

Two hours before service, mix the water and rice improver together until the improver has fully dissolved.
Add the rice and soak for a minimum of two hours (store ready for service).
Forty minutes before the dish is sent, add all the ingredients to the rice cooker.
Set to the cook programme and serve immediately once cooked.

nori powder

Blitz good-quality tinned nori in a high-speed blender to order.

season tuna

Trim the otoro of any thick sinew and dice.
Season with the tare and fold together gently with a spatula.
Keep in the fridge until needed.

finish

Season the cooked rice with the rice cutting mixture.
Grate wasabi to order, running a sharp knife through it to ensure a smooth texture.
Add a spoonful of the seasoned rice to the dish.
Top with a generous portion of grated wasabi and a spoonful of the seasoned tuna.
Cover with the blitzed nori and serve immediately.