Scale the fish if needed: Hold the fish by the tail and use the fish scaler or spoon to scrape the scales from the tail towards the head. Do this on both sides until all scales are removed. Rinse the fish under cold water.
Lay the fish flat on its side on a cutting board. The head should be facing away from your dominant hand if you’re right-handed, with the belly facing you.
Turn the knife so it is parallel to the backbone. Begin to cut along the length of the fish, keeping the blade against the spine to minimize waste. Use gentle, smooth strokes. Work your way from the head down to the tail, gradually separating the flesh from the bone.
