Remove scales and slime by scraping from tail to head using a sharp knife. Repeat for both sides.

Cut off the head diagonally behind the pectoral fins, ensuring the knife reaches the backbone. Repeat for the other side.

Make an incision along the belly from the head to the anus and remove the internal organs.

Cut into the membrane of the bloodline and scrape it clean. Wash and pat dry with kitchen paper.

Remove the fillet from the underside by sliding the knife along the backbone from head to tail. Repeat for the other side.

Remove the fillet from the topside by cutting along the backbone from tail to head, similar to the underside.

Trim off the belly bones by cutting thinly along the connection between the backbone and belly bones.