Wikipedia
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, 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 ( 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 , which can fall anywhere between July 18-August 8 each year.
The eel kabayaki is often served on top of a bowl ( donburi) of rice, and called unadon, the fancier form of which is the unajū, placed inside a tiered lacquered boxes called jūbako. It is also torn up and mixed up evenly with rice to make , which is enjoyed especially in the Nagoya area.