Filleting fish at home is useful for more than a neat fillet. You can check freshness, control the bones, and keep clean trimmings for stock: head without gills, backbone, fins, and tail.
Prepare the fish
Well-chilled fish is easier to handle: the flesh is firmer, the knife moves cleaner, and the skin is less slippery. Rinse the fish, scale it, remove gills and innards, then dry it thoroughly with paper towels.
Keep a board, a sharp filleting knife, tweezers, and a bowl for trimmings nearby. Discard the gills because they make stock taste muddy. The rest can be saved for fish stock if the fish is fresh and clean.
Remove the first fillet
Place the fish on its side with the tail toward you. Cut behind the gill cover down to the backbone, then turn the knife almost parallel to the board and guide it along the spine with short strokes.
The knife should glide on the bones. Do not try to cut through the whole fillet in one stroke; that tears the flesh. Open the fish gradually, lifting the fillet with your free hand and feeling where the backbone runs.
Remove the second fillet
Turn the fish over and repeat the same path. Near the tail, it helps to leave a small skin anchor so the fillet does not slide, then cut it free at the end.
On small fish, the second fillet can be harder because the body is less stable. Hold it with a towel instead of pressing your bare hand near the blade.
Bones, skin, and trimmings
Run your fingers along the center of the fillet to find pin bones. Pull them with tweezers in the direction they grow so the flesh does not tear. If the recipe needs skinless fillet, place it skin side down, cut near the tail, and slide the knife almost flat between skin and flesh.
Do not automatically discard the trimmings. Backbone, tail, and head without gills make good fish stock, but cook them gently and briefly to keep the flavor clean.
