Thornyheads, a type of rockfish, are popular in Japan for “nitsuke” preparation, in which they are simmered whole in a sauce of sake, mirin, water, soy sauce, sugar and ginger. Their size is suitable for whole-plate presentation.

There are three main species of thornyheads collectively known as “kinki” in Japan: the shortspine (Sebastolubus alascanus), longspine (Sebastolobus altivelis) and broadbanded (Sebastes macrochir). The shortspine and longspine species range from the Bering Sea …