Things You'll Need
Heavy-duty aluminum foil
Melted butter or olive oil
Halibut fillets or steaks
Both halibut and salmon are two popular fish entrees, and sometimes your family might demand both. The problem is that these fish cook differently because of their fat content. Halibut is a low-fat fish, with about 2 percent fat content; salmon, on the other hand, has about 12 percent fat content, one of the highest. Even though they cook differently, you can bake both fish together to save yourself time and work.
Purchase your fish, trying to keep the thickness of all the halibut even, and the thickness of all the salmon even. How long you cook a fish depends upon its thickness. For salmon, the rule of thumb is 10 minutes per inch in a 350-degree F oven. For halibut, it will take 14 minutes per inch of thickness at the same temperature.
Use a ruler to measure the thickness of your halibut and your salmon. You'll need to calculate how long each fish will need to be in the oven. Usually, the halibut will need to go in first, the only exception being if the salmon is significantly thicker than the halibut cuts. To calculate, multiply the halibut measurement by 14 minutes, and the salmon measurement by 10 minutes, to find out how long each will need to cook. For example, if your halibut is 1 1/4 inches thick, you would calculate 1.25 X 14. The answer is 17.5, so your halibut needs to cook 17 1/2 minutes. If your salmon is 1 1/2 inches thick, multiply 1.5 X 10, and you would get the answer 15 minutes. Add an additional minute or two to the cooking time of the fish that goes into the oven first, to account for opening the oven and letting out the heat when you put in the salmon. So if your halibut needs to cook for 17 1/2 minutes, and you add 2 more minutes to allow for the heat release, that would make a total cooking time of 19 1/2 minutes for the halibut. You would put the salmon, which only needs 15 minutes in our example, in the oven approximately 4 1/2 minutes after putting in the halibut.
Preheat your oven to 350-degrees Fahrenheit. Set a large baking tray aside. Cut some pieces of heavy-duty aluminum foil, a little more than twice as big than each piece of fish. Lay each piece of fish on the sheet of aluminum foil.
Brush your fish with melted butter or olive oil on all exposed surfaces. Season each fish to your desired taste. You may wish to sprinkle only salt and pepper on them. Some other good options are lemon pepper seasoning, Old Bay seasoning, citrus slices or chopping some fresh dill to sprinkle on them.
Starting with the fish that is going into the oven first, fold each piece in its aluminum foil to create a pouch. Pinch the edges of the foil together along the top and each end, and fold the edges over to seal the pouch. Place these pieces on one side of the baking tray and place them in the oven. Be sure to note the time you put it in, and calculate how long before the rest of the fish will be put in the oven.
Fold the foil for the remaining pieces of fish into pouches. When it's time to put them into the oven, put on your oven mitts, take out the baking tray and rotate it around so that the edge that was in the front of the oven is now in the back of the oven. Place the second fish pouches onto the other side of the baking tray. Put them in the oven and cook for the length of time the second fish needs to cook.
Remove the baking tray from the oven and allow the fish to rest for a couple of minutes. When you open the pouches, steam will escape, so keep your head back and protect your hands with oven mitts. Use a spatula to transfer each piece of fish to its plate.