In a small saucepan, on medium heat, heat your sake, mirin, red miso paste, and white sugar.
Bring to a slight boil and remove from heat after 8 minutes or until your sugar has dissolved. The sauce should be thick.
Preheat the broiler. Make sure the oven rack is 6 inches away from the broiler.
Line your baking sheet with foil. The foil will make cleaning easy.
Place fish onto the tray. Use paper towels to dry the fish.
Pour half of the sauce on the fish. Broil fish for 3 minutes.
After 3 minutes, remove the tray and pour the remaining sauce on the fish.
Put it back under the broiler. Broil for another 5 minutes. You should get a lovely caramelized fish.
Serve and enjoy!
