To Prep
In a saucepan, combine the sake and mirin together and heat over a medium flame till they begin to boil. Boil for 30 secs before turning the heat down to low and adding in the miso paste.
Allow the miso to dissolve before adding in the sugar and continuing to cook till the sugar has dissolved too.
When the mixture has been well combined, remove the saucepan from the heat and set aside to cool.
Dry the fish using paper towels before placing in to a zip lock bag and covering with the miso mixture. Squeeze the bag to coat the fish and let marinate overnight.
When the fish has marinated, remove them from the zip lock bag and wipe off the excess marinade.
To Cook
In a non-stick pan over a high heat, add oil and place the fish skin side down to sear until the skin begins to slightly blacken.
Flip the fish and continue to cook the other side for about 2 mins until the flesh has cooked through. Remove and set aside.
To Serve
Serve topped with a small serving of pickled ginger and rice!