When talking about mahi mahi, she says, "I prefer to season by lightly rubbing oil on all sides of the filet, and seasoning with salt and pepper." The tip will apply to all white fish, however.
2 fillets (total of 250 grams) of white fish (sawara in this article), base seasoning for fish (1/4 tsp salt, pinch of pepper, 1 Tbsp sake, 1 Tbsp), katakuriko starch, mixed seasoning (1 and 1/ ...