Scaling and cleaning
Put a few layers of kitchen paper on your work surface or chopping block. Using a blunt knife, scrape away the scales from tail to head. Rinse thoroughly under running water.
Cleaning a round fish
Take a sharp knife and split the fish along the belly. Scrape out the entrails (inner parts). Cut off the head, just below the gills. Cut away the fins. If you want to fillet and skin the fish, leave the tail. Rinse again with cold water.
Cleaning a flat fish
With the point of your knife, make an incision just behind the head on the upper (dark) side. Scrape out entrails and rinse.
Filleting A round fish will give you two fillets; a flat fish, four. Hold the fish by its tail and, using a sharp knife, cut along the backbone. With round fish, turn skin down and lift off the backbone gently, running the knife along behind it as you raise it. Pick off any smaller bones that have not come free.With flat fish, cut round behind the head and free the two upper fillets from the backbone, using the knife. Turn the fish over and repeat the process.
Skinning First sprinkle salt on your fingers so you can get a firm grip on the fish’s tail. To skin round fish Make an incision just below the head, then loosen the skin. Pull it towards the tail, easing it up by running the blade of a knife underneath it. Pull the skin off gently, using the knife when you need it. To skin flat fish Again, sprinkle salt on your fingers so you can grasp the tail firmly. Make a slit and pull off the skin towards the head. Turn the fish over, and skin the other side.