Miso Glazed Fish

1/4 cup Mirin
1/4 cup Sake
3 Tbsp white or yellow miso paste
1 Tbsp sugar
2 tsp sesame oil
4 6 oz pieces of firm fish - Cod, Salmon, Mahi

1.  Combine the mirin and sake in the smallest saucepan you have and bring to a boil over high heat. Boil 20 seconds, taking care not to boil off much of the liquid, then turn the heat to low and stir in the miso and the sugar. Whisk over medium heat without letting the mixture boil until the sugar has dissolved. Remove from the heat and whisk in the sesame oil. Allow to cool. Transfer to a wide glass or stainless steel bowl or baking dish.
2. Pat the fish fillets dry and brush or rub on both sides with the marinade, then place them in the baking dish and turn them over a few times in the marinade remaining in the dish. Cover with plastic wrap and marinate for 2 to 3 hours, or for up to a day.
3.  To cook the fish, broil on high heat 2-3 minutes per side until cooked through.