How to Make Seared Ahi Tuna. Known for its buttery texture, mild flavor and rich color, ahi (or yellowfin) tuna can be seared to surround its raw center with a tasty caramelized crust. Make seared ahi to serve over a simple salad, as an appetizer or a satisfying substitution for a traditional steak.
Purchase fresh, sushi-grade ahi since you'll be eating it partially raw. Look for firm, ruby red flesh with a clean smell of the sea. There should not be a "fishy" odor.
Sprinkle and press salt and fresh ground pepper onto both sides of the tuna steak. You can also season the fish with a spice blend or soak in a marinade to suit the particular recipe.
Heat a heavy-bottomed frying pan. Use high heat if searing a steak 1/2-inch thick or less and medium-high for thicker pieces.
Add 1 1/2 tsp. of olive oil to the pan. Using too much will lead to a greasy tuna steak. You can also cook the fish in butter, but it must be "clarified" (meaning, melted and removed from its milk solids) so it will reach the temperature necessary for searing without burning.
Place the fish in the pan once the oil begins to smoke.
Turn the fish after about 2 minutes or when the bottom 1/4 has turned from red to whitish-pink. Flip the steak and cook for 1 to 2 minutes on the other side.
Let the fish cool for a minute before cutting into smaller chunks or thin slices that showcase the pink center.
Garnish with fresh herbs and lemon slices. Check websites (like AllRecipes and FoodNetwork) or seafood cookbooks for sauces and side dishes to accompany the seared ahi (see Resources).
After placing the ahi in the pan, don't move the fish immediately or you may tear the flesh or prevent a complete sear.