Yummy Herb and Garlic Grilled Tuna Steaks for dinner! Recipe: Preheat grill or broiler on high. Rinse tuna and pat dry. Set aside. Combine tarragon, garlic, and lemon peel in a small bowl; mix well. Set aside. Season tuna with salt and pepper if desired. Drizzle with oil; rub rosemary mixture into both sides of tuna. Let rest 5 minutes.⠀Grill (or broil) tuna for 2 to 5 minutes on each side, or until desired doneness.