This recipe originally came from Allrecipes.com.

4 6-ounce yellowfin tuna steaks
1/2 cup vegetable oil
1/3 cup soy sauce
1/4 cup fresh lemon juice
2 teaspoons Dijon mustard
1 teaspoon grated lemon peel
1 clove garlic, crushed

4 wedges lemon, for garnish

Prick tuna steaks all over with a fork and place in shallow glass dish.

Whisk oil, soy sauce, lemon juice, Dijon mustard, lemon peel, and garlic together in a bowl; pour over the tuna steaks. Cover dish with plastic wrap and refrigerate 1 to 3 hours.

Preheat grill for medium heat and lightly oil the grate.

Remove tuna from the marinade. Shake excess moisture from the steaks.

Pour the marinade into a small saucepan and bring to a boil. Reduce heat to medium-low and cook marinade at a simmer for 10 minutes.

Cook tuna on preheated grill, basting with boiled marinade, until cooked through, 5 to 6 minutes per side. Serve with lemon wedges.