Thanks for the recipes, guys. the Thai one in particular looks great, and I will try that in future.
The head I had ended up being slowly steamed (3 hours or so on very low) over a little liquid in a closed pot (foil pressed over the fish) containing a couple of large local garlic cloves, couple of large shallots (my garden), two inches of spicy ginger (my garden) an inch of fresh turmeric (my garden) a coupe of extra hot birds eye chillies (my garden) a couple of inches of fresh galangal (my garden), a splash of organic soy, a half cup of mirin, a sprig of pepper corns, and a healthy splash of Thai squid sauce (like fish sauce but more stinky).
Yum.
the rest of the fish appeared variously as a ceviche of tuna belly, heaps of really soft sashimi, some teriyaki steak, and a Taiwan-Japan hybrid soup made from the meaty bones and the collar with miso and Chinese cabbage and enoki mushrooms and white pepper and garlic.