A serving of cooked fresh tuna is low in saturated fat and cholesterol, high in protein and rich in nutrients like selenium, vitamin B-12, vitamin B-6 and niacin. It is also a good source of omega-3 fatty acids, providing more per serving than cod, tilapia or catfish. A typical tuna steak cooks in less than 15 minutes and can be prepared in a variety of ways, including in the oven. Whenever possible, choose fresh yellowfin, bigeye or albacore tuna that has been caught in the United States or skipjack tuna that has been troll- or pole-caught in any ocean. According to the Monterey Bay Aquarium Seafood Watch, these types of tuna are caught in environmentally responsible ways.
Coat a rimmed baking sheet with cooking spray or a thin layer of olive oil.
Pat each tuna steak dry with paper towels. Use a ruler to determine the thickness of the steaks.
Arrange the fish on the baking sheet. Brush each steak with olive oil and season them with salt, pepper and your choice of spices and herbs, such as freshly minced rosemary.
Preheat the oven to 450 degrees Fahrenheit. Bake the tuna steaks for approximately 10 to 12 minutes per inch of thickness.
Make a small cut in the center of one of the tuna steaks using a thin-bladed knife. Determine if the tuna has reached your desired level of doneness. Insert a meat thermometer into the steak to confirm that the fish has reached 125 degrees Fahrenheit.