best thread i've seen in a LONG time.. i'd use his elboy-fin things and make some sharp soup.. Then I'd make suishi out of his meaty parts (chest, abs, thighs).. then i'd fillet the rest of the body (strip off pieces of meat like cutting a cucumber from his calfs, any remaining on his chest,back,shoulders, ect. And finally I'd cut out each part of his head - cheeks, peel off his forehead, stew the gills (gills contain a LOT of flavor), and bread-fry each of those bits using with the gill oil I created from his neck.
pretty much sums it up..
Also fish eyes are extremely nutritious so I'd probably throw keep that in case I was low on energy one day.