Baking on a sheet provides a quick way to prepare tilapia, an inexpensive, widely available and sustainably raised fish. You can buy tilapia fillets fresh at the seafood counter or frozen in the freezer aisle. If you buy frozen, thaw it in the refrigerator before you bake for best results. Thanks to tilapia's mild flavor, the options for marinades, seasonings and sauces are endless.
Preheat your oven to 400 F while you prepare the tilapia. Spray the baking sheet with a nonstick cooking spray or coat it lightly with a light-colored oil -- such as vegetable or canola oil -- before placing the fillets in a single layer on the sheet. Tilapia fillets are typically thin, which means they'll bake quickly in 15 to 20 minutes, depending on the temperature of your oven and the thickness of the fillet. You can test for doneness by using a fork to try to flake apart the thicker end of the fillet; if it flakes easily, it's done. Another indication that it's ready is that the fillet is firm to the touch and opaque.
Broiling provides another option. Coat the baking sheet with nonstick cooking spray or oil, arrange the fillets in a single layer and place the sheet under a preheated broiler for five to 10 minutes until it turns a light golden brown and flakes easily with a fork. This method works well when you've breaded your fillets with breadcrumbs or cornmeal, as the broiler crisps up the coating.
For an engaging presentation, create individual serving packets of tilapia by placing one fillet in the center of a large square of foil and topping it with olive oil or butter and your desired flavorings. You can also add thinly sliced onions, green beans or other quick-cooking vegetables. Close each packet by bringing two sides together above the contents and folding down several times, then folding the open ends inward several times. Place the packets on a baking sheet and bake at 425 for about 20 minutes. Be careful when opening the packets as hot steam will escape.
Since it has such a mild flavor, tilapia lends itself well to a variety of seasonings and marinades -- from light and citrusy, to blackened and spicy, or anything in between. If you choose to marinate tilapia, thaw it first and marinate it for only 15 to 30 minutes so as to preserve its delicate texture. Keep a close eye on tilapia during broiling, as it can go from done to burned quickly. If you're hesitant to attempt broiling, try moving your oven rack down another notch so the food is a little further away from the direct heat; this will increase the cooking time but reduce the risk of burning.