Mix the marinade (mirin, sake, white miso and sugar) until it's smooth and place the fish in, skin side down
Marinate in the fridge for 72 hours
Place an oven-safe pan on the stove on medium heat and place the fish flesh side down, cook until you have nice colour (4-5 minutes)
Place into 180°C oven for 7-8 minutes or until cooked through
Serve with rice and Asian greens
