Stir together the miso, mirin, sugar and
sake, if using. Place the salmon fillets on a
plate or in a medium food bag and cover
with the miso marinade. Leave in the fridge
for at least 30 mins or, better still, overnight.
Heat oven to 200C/fan 180C/gas 6. Lightly
oil a baking tray. Use kitchen paper to wipe
off the marinade (don’t be tempted to wash
it off as you will lose some of the flavour).
Place the fillets on the baking tray, skin side
down. Cook in the oven for 15 mins until the
fish flakes easily and is cooked through.
Meanwhile, make the cucumber salad.
Using a vegetable peeler, shave the
cucumber into long, thin ribbons. Whisk
together the rice wine vinegar, oil and sugar.
Toss the cucumber ribbons in the dressing,
then curl them up on two plates. Serve
with the salmon and some plain white
rice sprinkled with toasted sesame seeds.