Yellowfin tuna, also known as ahi tuna, is a large fish found in tropical and subtropical deep waters. Ahi tuna is often used in sushi, eaten raw. Yellowfin tuna steaks are low in fat with a soft flesh. Using the George Foreman Grill reduces the amount of oil needed to cook the fillet, further reducing fat intake. A mild seasoning helps offset the fishy flavor that increases when cooking yellowfin tuna.

Mix the ingredients for your marinade in the bowl. Commonly-used marinades include salt, black pepper, green onions, soy sauce and ginger. You can make a more tropical marinade by adding pineapple or orange juice.

Apply the marinade to the fillet. Store in an airtight container for two to six hours.

Turn the George Foreman Grill on high. Wipe the grill with a little olive oil using a towel, just enough so the fish doesn't stick.

Place the tuna fillet on the center of the grill, cooking for three to four minutes. The fish contacting the grill will get white at the bottom and opaque in the center.

Flip the fish. Cook for another three minutes or until the fish is white throughout.