Ahi tuna only takes a few minutes to prepare in a frying pan and can be served in a variety of ways. Ahi tuna comes from the yellowfin tuna fish, found in tropical waters around the world. The firm, bright red flesh has a mild flavor and is typically served raw as sushi. It is also delicious when pan-seared, which leaves most of the interior rare or medium-rare, though you can fully cook it as well. Purchase sashimi-grade ahi tuna from a fish market, if possible, as it is flash frozen to kill any parasites so you can eat it rare with confidence.
Remove the ahi tuna steaks from the refrigerator 30 minutes to an hour before you plan to cook to allow them to come to room temperature.
Heat a skillet on the stove to high heat. For searing, the frying pan needs to be extremely hot -- it's ready when it's too hot to hold your had a few inches from the skillet's surface.
Brush the ahi tuna steak with olive oil on both sides. Season lightly with salt and pepper. Add optional seasonings such as garlic and chili powder, or brush the steaks in soy sauce in addition to the olive oil, if you wish.
Add the ahi tuna to the hot skillet and sear on both sides between two and five minutes, depending on how cooked you want the ahi tuna to be. If you plan on cooking it fully through, reduce the heat to medium after searing and flip the tuna over a few times for even browning until cooked through. Slice the tuna into 1/4-inch thick slices before serving.