Frozen fish does not need to be thawed before it is cooked. However, cooking fish that has not been thawed does add slightly to the cooking time.
Frozen fish should be rinsed under cold water before cooking. Rinsing the fish aids in removing any accumulated ice on the fish.
Fish needs to be dried with a paper towel. Olive oil or marinade should be brushed on the fish before cooking.
Frozen fish can be boiled, steamed, grilled, poached or baked. Thawed fish is easier to prepare and requires less cook time. Fish can also be partially thawed in cold water in the sink.