How to Fillet a Fish

Filleting a fish involves cutting it in such a way that the two (or in the case of flatfish, four) resulting pieces of fish don’t contain any bones. Fish may be filleted before it’s cooked, though if you are presented with a whole cooked fish, you can use the same filleting techniques to eat the fish without ending up with a mouthful of bones. Filleting takes some precision—first attempts can be frustrating, but it becomes much easier with practice. The methods used to fillet oval fish and flatfish are somewhat different. Both are explained here.

If you’re filleting an uncooked fish, gut the fish first to avoid soiling the flesh. Before filleting the fish, rinse it quickly but thoroughly under running water.

How to Fillet an Oval Fish

The term oval fish refers to those fish that have a “regular” fish body (as opposed to a flat body), such as salmon, trout, tuna, and most other species of fish.

Turn the fish on its side, with the head facing toward you. Make an incision in the middle of the back (as deep as the backbone) from the tail to the back of the head.
Starting from the tail, slip the knife just above the backbone so that the tip runs above the ribs and down to the cavity you opened by gutting the fish. With the knife inserted in this way, cut toward the head up to the gills.
Detach the fillet from the head by cutting it behind the gills.
If you wish to remove the skin from the fillet, hold the end of the tail firmly and make an incision about 3/4" from the tail. Slip the knife in and, holding the knife at a very shallow angle, gently separate the skin from the flesh by sliding the knife along the length of the fillet.

After you finish filleting one side of the fish, Turn the fish over and repeat the process to remove the second fillet from the other side.

How to Fillet a Flatfish

The term flatfish refers to fish, such as flounder, that in adulthood have a horizontal body. These fish dwell at the sandy bottom of the ocean, with their flat bottoms against the sand, and both of their eyes on their top side.

Start skinning the fish by cutting into the skin near the tail.
Using a cloth, pull the skin back as far as the head.
Make a lengthwise incision in the center of the fish (as deep as the backbone) to divide the side of the fish that you’re cutting into two fillets.
Insert the blade of the knife between the flesh and the backbone, with the tip of the knife running just above the ribs. Detach the flesh gently from the backbone and ribs.
Detach the outer edge of the fillet from the lateral bones by running the blade along its entire outer length.
Remove the other fillet on the same side by following the same procedure. Then turn the fish over and repeat the process, producing a total of four fillets.