Make sure your fillet is as fresh as possible and bought from a reliable fishmonger.
Mix the salt and sugar together in a small bowl.
Remove the skin from the fish and lightly coat both sides of the fillet with the salt mixture, place on a non-reactive tray and cover with cling wrap.
Place the fish in the fridge for two hours to lightly cure.
Wash off the cure with cold running water and pat dry with paper towel.
Working on a slight angle, thinly slice the fish making sure to make single clean cuts.
Thinly slice the daikon with a vegetable turner.
Pick the shiso leaves.
Crush the mountain pepper with a mortar and pestle.
Place the daikon and fish on a small plate.
Garnish with shies herbs.
Sprinkle the freshly ground mountain pepper.
Serve straight away.
*Please note: as this recipe calls for uncooked fish, please make sure your fish is purchased from a reliable fishmonger and is handled correctly. It is advisable for people at high risk to not eat raw fish.