Cooking frozen salmon fillets is fairly simple because salmon is a very forgiving fish. The oily texture of the flesh holds up well when it is frozen and thawed, and it is very difficult to overcook. Frozen salmon fillets fare best if they are quickly pan-seared, then finished off in the oven. This allows the fillets to maintain a firm texture without becoming overdone on the outside, especially if they are still a bit cold inside.

Thawing the Salmon

Thawing frozen salmon fillets is easy, but requires some care so that the salmon does not go bad as it thaws. Most frozen salmon fillets come packaged individually in vacuum-sealed plastic. The best and safest way to thaw the fish is to put the wrapped fillets in a bowl or pan and place them in the refrigerator overnight. The gradual process will keep bacteria at bay. If you need to thaw the salmon more quickly, place the wrapped packets in a bowl of cool water and leave it out on the kitchen counter. Thawing salmon fillets in this manner should take only an hour or two. Whatever you do, never leave frozen salmon in a room-temperature environment to thaw. This encourages bacterial growth. Thawed fish should be used within 24 hours.

Preparing the Salmon

Seasoning frozen salmon fillets requires little more than salt and pepper, though you may add some Cajun or lemon-pepper seasoning blend if desired. Shake about 1/2 tsp. of the seasonings on each side of the fish and massage them into the flesh with your fingers. Don't prepare frozen salmon fillets until it's time to cook; some seasonings that are heavy on sodium can break down the fillets and make them mushy.

Cooking the Salmon

Cooking frozen salmon fillets first on the stove, then in the oven, allows the fish to remain moist and firm. It's best to use an ovenproof skillet to sear the fillets so that you can move it directly to the oven instead of attempting to transfer the delicate fish. Heat 2 or 3 tbsp. of oil in the skillet over high heat, then lay the fish skin-down in the oil. Cook for about four minutes over high heat, turn over the fillets. Immediately transfer the skillet to a 450 degrees F oven and continue cooking the salmon for about another four minutes.

Checking the Salmon

Use a meat thermometer to determine if salmon is ready to eat. According to the FDA, cooked seafood should be heated to an internal temperature of 145 degrees F before it is consumed. If you do not have a meat thermometer, slip the point of a sharp knife into the center of a fillet and pull the flesh aside slightly. If the salmon is flaky and opaque, it is ready. If it is too firm or stringy to pry apart easily, it needs another minute or two.

Source:

"Salmon: A Cookbook"; Diane Morgan; 2005

U.S. Food and Drug Administration: Fresh and Frozen Seafood: Selecting and Serving It Safely