Minutes count when cooking fish. Cooked perfectly, fish will be moist and tender. Fish is done when it begins to flake easily with a fork and loses its translucent or raw appearance. A useful guideline is the 10-minute rule—allow 10 minutes for every inch of thickness. Measure fish at its thickest part—if fish is stuffed or rolled, measure it after stuffing or rolling. Add 5minutes to the total cooking time if you are cooking fish in foil or if the fish is cooked in a sauce. Double the cooking time (20 minutes per inch) for frozen fish that has not been thawed. This handy 10-minute rule applies to baking, broiling, sautéing, steaming or poaching fillets, steaks or whole fish. (Do not apply the 10-minute rule when microwaving fish.)