Despite the orgiastic feasting on hirame, there was plenty of fish left over for later use. First up was engawa, the wings of the fillets, which I made into sushi.
One way to enjoy filletted fish without cooking it is in kobu-jime, where the fish is salted lightly and then pressed between two fronds of kobu kelp. It comes out cured and very well flavoured and perfumed by the kelp, and you can control the strength of the flavour by how long you keep the fish wrapped in kobu; usually I go for 24 hours for a middling taste. This I always eat with the chopped up flesh of umeboshi plums.
Filletting fish for sushi or sashimi invariably leaves you with the skin leftover. Most restaurants and sushi chefs will toss this away (there are some notable exceptions to this) but with bigger fish like hirame or tai the skin is actually pretty tasty grilled, fried or poached. I like mine deep-fried and send it down with a couple of cold beers.
The last remnants of the hirame were consumed in that highly traditional Japanese dish fish pie.
There are plenty of recipes and versions of this online, but mine is pretty simple: a layer of raw spinach leaves, layer of raw white fish sprinkled with a touch of salt, white pepper and some grated nutmeg, then a layer of chopped up hard-boiled eggs, a sprinkle of chopped parsley, then cover the lot in Bechemel sauce. The whole is topped off with freshly made mashed potatoes (mine contains wasabi!) and a little Cheddar cheese sprinkled over the top.
Cook in the oven at 180°C till bubbling and nicely browned on top. Serve with Worcester sauce and/or chilli sauce.