Kabayaki

Kabayaki (蒲焼^?) is a preparation of fish, especially unagi eel, where the fish is split down the back (or belly), gutted and boned, butterflied, cut into square fillets, skewered, and dipped in a sweet soy sauce-based sauce before being broiled on a grill.

Besides unagi, the same preparation is made of other long scaleless fish such as hamo (pike conger),dojō (loach), catfish,anago (conger eel), and gimpo (^?) (Pholidae). One can also find canned products labeled as kabayaki-style sanma (Pacific saury).

Kabayaki eel is very popular and a rich source of vitamins A and E, and omega-3 fatty acids. A popular custom from the Edo period calls for eating kabayaki during the summer to gain stamina, especially on a particular mid-summer day called doyō-no ushi-no-hi^[] (土用の丑の日^?), which can fall anywhere between July 18-August 8 each year.

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Wikipedia