Boneless, skinless tilapia can be lots of fun to work with in the kitchen, given that it's so mildly flavored you can do just about anything you want to it. A frozen filet won't cook evenly, leaving you with rubbery parts and possibly an undercooked center. Fortunately, a tilapia filet can thaw in little more than the extra time you'd need to cook a frozen one through in the oven. This thin, fragile, flaky fish cut is tricky to cook on the stove or grill, so if you're looking for an easy preparation, bake or broil it. Tilapia is naturally moist, so it handles dry heat well.
Keep the frozen tilapia in its original airtight packaging. Fill a large bowl with cold water and submerse the fish for about 20 minutes to thaw it.
Preheat the oven to 450 degrees Fahrenheit as soon as you start defrosting it if you're baking the tilapia. Preheat the broiler for about the last 10 minutes of the thawing time if you're broiling the filet.
Line a baking tray or the bottom of a broiler pan with parchment paper or aluminum foil. Apply a thin coating of nonstick spray to the lining of the baking tray or to the rack of the broiler pan.
Remove the tilapia from its packaging and pat it dry with paper towels, then season it however you like. A coating of basic herbs, spices and aromatics works just fine for a simple preparation; possible ingredients include salt, pepper, citrus fruit zest, minced garlic or garlic powder, minced ginger, thyme, rosemary, tarragon, marjoram, parsley, turmeric, coriander, curry powder, chili powder, blackening seasonings, pre-mixed seafood seasonings or many more. For other ideas, spread on honey, teriyaki sauce or soy sauce; dredge the filet in flour, then beaten egg and then seasoned breadcrumbs or finely chopped nuts; or top the fish with a bit of mango or other topical fruit chutney.
Place the filet on the lined baking tray or the greased rack of the broiler pan. Bake the fish in the middle of the oven; broil it with its surface 5 inches below the broiler at the top of the oven. Bake the tilapia for about 8 to 10 minutes or broil it for about 5 to 8 minutes, just until its flesh is flaky and opaque all the way through. Fish should be cooked to an internal temperature of 145 F, as measured with an instant-read food thermometer, per the recommendation of the U.S. Department of Agriculture.