I got just over 1lb of Chilean sea bass for two servings. Since I did not have much Saikyo miso 西京味噌 left, I used white miso with mirin and sugar. Again, the exact proportion is a bit iffy and I have to guesstimate; white miso (3 tbs), sugar (1tbs), yuzu juice (from the bottle, 1 tsp) and mirin (2 tbs or until right consistency is reached). I marinated the fish in a Ziploc bag in the refrigerator for several hours. I removed the miso marinade by rubbing the surface with my hand so that a small amount of the marinade remains on the surface. I baked it in a 350F convection oven for 30 minutes on a metal rack set on the top of the deep baking pan so that hot air could circulate underneath the fish.
The fish is very nice--oily with a soft flaky texture and a nice sweet miso flavor. Among the many other fish which can be over cooked so easily ending up dry, this is an exceptionally good fish. I served it with asparagus tips blanched and dressed with sesame sauce (sesame paste, sugar and soy sauce).