Frozen tuna, providing it was frozen at sea, is often better than fresh tuna steaks, which can be 7 to 10 days old when you buy it at the store. Tuna is a large oily fish with a strong flavor and meaty flesh, well-suited to being served as a thick steak. Cover and bake frozen or defrosted tuna steaks rapidly at a high temperature to prevent drying out during the cooking process. Ensure the fish is thoroughly cooked before serving by testing the internal temperature with a meat thermometer.
The U. S. Food and Drug Administration says if you defrost frozen tuna before baking, you should thaw the fish in a refrigerator overnight. Never leave fish to defrost on a countertop or anywhere at room temperature. When raw fish is exposed to warm air, bacteria and food-borne pathogens multiply, increasing the possibility of food poisoning. The Cook's Thesaurus says perishable food left out for more than two hours at 40 to 140 degrees Fahrenheit is regarded as unsafe to eat.
Wash your hands with soap and water before and after handling raw fish to prevent contamination of other food items, and clean surfaces after using them to prepare raw food and before preparing other ingredients. BBC GoodFood advises against washing tuna before use and recommends that you simply pat it dry with clean paper towels before using it in a recipe.
Baking a Defrosted Tuna Steak
Preheat the oven to 450 degrees. Place the tuna steak on a piece of aluminum foil and season to taste with salt, pepper or a selection of herbs. Wrap the foil into a loose parcel and place in the middle of the oven, directly on the shelf. Bake for 10 minutes per inch of thickness. Remove the foil parcel from the oven and ensure the tuna is cooked before serving. The flesh should be opaque and flake easily when pressed with a sharp knife.
Cooking a Frozen Tuna Steak
Allow extra cooking time if you bake a frozen tuna steak. Ensure the fish is thoroughly cooked by testing the internal temperature of the tuna steak with a meat thermometer. Properly cooked tuna should be 145 degrees Fahrenheit at its thickest point.