The most important fact in choosing fish is freshness. A fresh fish will not smell fishy; a fishy smell means improper handling. A fresh fish has a mild odor, firm flesh, clear eyes, pink gills and shiny scales. When you buy steak or fillets look for flesh that is not yellow and brown around the edges. If you buy frozen fish make sure you don’t buy anything that has been defrosted for more than two days. It is better to buy frozen fish and defrost it at home.
There are two categories of fish: lean and oily. Lean fish has a mild flavor, white flash and contains 5% or less fat. Sole, flounder, turbot, cod, Pollack, sea bass, rock fish, snapper, drum, bass are examples of lean fish.
Oily fish contains 5 to 50 percent fat. Their flesh is usually richer and stronger and have less white flesh. The oily fish are swordfish, salmon, tuna, trout, and catfish.
Steaks are cross-sections cut from a whole fish. To cut a steak use a large, sharp knife cut off the head just behind gills. Slice the fish into steaks of the desired thickness, usually between 1 and 1 1/2 inches.
Fillets are long pieces of boneless fish. To fillet a round fish, make a slit along backbone from head to tail. Then cut behind gill. Hold the head, insert knife between fillet and ribs. Slide knife along ribs, cut down the fillet. Pull fillet free and sever skin at the anal fin. Repeat the process on the other side of the fish.