How to Cook a Tuna Fillets in the Oven

Oven-cooked tuna fillets are a healthy was of preparing the fish..
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Fatty fish provides unsaturated fats, including omega-3 fatty acids, protein and several vitamins and minerals with relatively few calories and low saturated fat content. Tuna, like salmon, mackerel, trout, herring and sardines, is a fatty fish. The American Heart Association suggests having fatty fish at two or more meals every week. Tuna fillets are quick and easy to prepare a number of ways, including by baking them in the oven. Recipes are plentiful and varied, since tuna fillets are versatile enough to support a wide range of flavor accompaniments.

Step 1

Refrigerate the tuna fillets for at least 24 hours to thaw them if they're frozen.

Step 2

Rinse the tuna fillets with cold water and blot them dry with clean paper towels.

Step 3

Preheat the oven to 450 degrees Fahrenheit.

Step 4

Season, glaze or marinate the tuna fillets as you like them, or by following a chosen recipe. For a basic seasoning option, brush the tuna fillets with cooking oil, squirt them with lemon juice, and then dredge them in sea salt, freshly cracked black pepper and a favorite fresh herb or two.

Step 5

Grease a baking tray with cooking spray or oil. Place the tuna fillets on the tray without letting them touch each other or the sides of the tray. Place the tray on a middle tier in the oven.

Step 6

Bake the tuna fillets for four minutes per inch of thickness to cook them to rare, five minutes per inch for medium-rare or six minutes per inch for medium. Refrain from cooking them more, as they start to dry out past medium. Cooking times vary by a number of factors, so use a meat thermometer to determine when the tuna fillets are done. Take them out at 120 degrees Fahrenheit for rare, 130 degrees for medium-rare or 140 degrees for medium.

Step 7

Remove the tuna fillets from the baking tray with tongs or a spatula immediately to prevent overcooking. Serve them right away.

Things You'll Need

  • Paper towels

  • Seasonings

  • Baking tray

  • Cooking spray or oil

  • Meat thermometer

  • Tongs or spatula

  • Tuna fillets


For a simple tuna glaze, bring 3/4 cup of soy sauce and 1 tablespoon of honey to a boil, and then spoon it over the tuna fillets and spread it over them evenly.

For an easy tuna marinade, soak the tuna fillets in red wine, soy sauce or a citrus juice for one to four hours in a covered glass baking dish in the refrigerator. Flip them over once halfway through.

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