This recipe requires a fish that can handle the grill. If you can't find good fresh tuna, choose mahi mahi or amberjack. Although the flavor will be different because of the oils in the fish, it is still yummy. Prep time does not include 1 hour marinating time or time to get coals ready in the grill. Cut the cooking time for mahi mahi or amberjack...it isn't as dense as tuna.