Kohada is a type of herring, and when you eat it as sushi, it is generally marinated in vinegar.
Soak the whole fish in water before you prepare it.
Remove the dorsal fin and descale starting from the tail to the head. At the black spots behind the head, cut off the head.
Cutt off the belly, being careful not to remove too much. Scrape out the entrails, then wash thoroughly.
Cutting along the backbone, insert the knife into the belly to open it out.
Putting the belly side down, insert the knife between the flesh and bone at the head to remove the bone and tail. then, slice off the small bones along the belly, working at right angles to the fish.
To marinate the fish, place the fillets on a shallow dish (glass or porcelain) sprinkled with salt. Then, sprinkle with salt and rest in a cool place for 30 minutes. Rinse and drain, and marinate in vinegar with the skin side down for about 5 minutes.
Drain and let rest for 30 minutes.
Cut the tail and the hard part along the dorsal fin, then make cross cut incisions in the skin, as decoration. You can also make wavey cuts.
Ready for sushi!