how long do i need to cook fish in the oven
1 Pan-dressed fish is a dressed fish with the head and tail removed. 2  Weigh a dressed or pan-dressed fish before cooking, then bake, uncovered, in a preheated 350 degrees F oven for 6 to 9 minutes per 8 ounces.. How to prep the fish. 1  If fish is frozen, allow enough time for it to thaw, covered, in the refrigerator. 2  Preheat the oven to 450 degrees F for fillets or steaks or 350 degrees F for dressed fish.