• Gather all the ingredients. Select the freshest fish possible, as you will be marinating this fish for a few days.
  

To Marinate the Fish (two to three days before serving)

• Sprinkle salt over the fish and set it aside for 30 minutes. The salt will draw out excess moisture and reduce the odor of the fish.
  
• In a bowl, add the saikyo miso, mirin, and sake (and sugar, if you are using regular white miso.)
  
• Mix it all together and pour the marinade into a flat-bottomed airtight container.
  
• Pour 2 Tbsp sake over the fish to rinse off the salt. Gently pat dry with a paper towel to remove the moisture. Do not wash the fish under running water.
  
• Place the fish in the container and coat both sides of the fish with the marinade.
  
• Slather the fillets with the marinade. Cover the container and keep it in the refrigerator for up to 2-3 days. If you prefer your fish less salty (and don’t eat this dish with rice, for example), you can reduce the marination time to 1 day (or even several hours.) It depends on your preference.
  

To Remove the Fish from the Marinade

• With your fingers, wipe the marinade off the fish completely. Do not leave any excess marinade on the fish; otherwise, it will burn easily. At this point, you can individually wrap the fish with plastic wrap and store it in a freezer bag for up to 2-3 weeks. Defrost in the refrigerator before cooking.
  

To Prepare the Fish for Cooking

• Place the fish skin side up on a baking sheet lined with parchment paper/silicone mat (for baking) or foil (for broiling).
  

To Bake (Recommended)

• Preheat the oven to 400°F (200ºC) with a rack placed in the center of the oven. For a convection oven, reduce the cooking temperature by 25ºF (15ºC). Bake the fish on the parchment paper until the surface is blistered and browned a bit, about 20 minutes. You do not need to flip the fish.
  

To Broil (Optional)

• Preheat the broiler* with a rack placed about 8 inches (20 cm) away from the top heating element (in the center of the oven) for 5 minutes. When broiling, you don't control the temperature in the oven; instead, you control the distance between the broiler and the surface of the food. It's similar to using hotter and cooler zones on your grill. *There are usually three broiler settings: Low (450ºF/232ºC), Medium (500ºF/260ºC), and High (550ºF/288ºC). I usually use the Medium (6 inches away) or High (8 inches away) setting.
• Place the fish on the foil-lined baking sheet and broil on High (550ºF/288ºC) for 8-10 minutes until the surface is blistered and browned a bit. Please remember the cooking time varies depending on the thickness of the fish and the distance between the broiler and the food. You do not need to flip the fish.

To Serve

• Carefully remove the fish with a spatula and remove any burnt miso from the fish. Serve immediately. I serve the fish with thinly sliced red radishes and garnish it with a small green leaf from my backyard for additional color.
  

To Store

• You can keep the cooked leftovers in an airtight container and store it in the refrigerator for 3 days and in the freezer for up to a month.