Spanish mackerel kenchin-style grilled

For Sawara Kensen-yaki (Spanish mackerel stuffed with a julienned vegetable filling), the bisha-tama that forms the base of the kensen filling is made noticeably sweeter than usual, with just a small amount of light soy sauce and some sugar added. Keep it in a soft, half-set state so it doesn't firm up, and slowly work it over quite low heat; into this you mix bamboo shoot, carrot, and wood ear mushroom that have been boiled and pre-seasoned, all cut into thin strips. Since this is finally stuffed into the sawara and baked, at this stage you don't cook it through completely — bring the heat in just a touch further than half-set, combine it with the vegetables, stuff it into sawara that has been butterflied open, and bake it in the oven.

Marinate the sawara beforehand in sake, soy sauce, and mirin, then lay it on a sushi-rolling mat (makisu), place the kensen filling on top, and roll it up. To keep it from sticking, wrap it further in aluminum foil brushed generously with oil, folding in both ends, and bake it in the oven in that state.