1In a small bowl mix oil lime juice tequila OLD BAY and cilantro. Place tuna steaks in large resealable plastic bag and add marinade. Turn to coat well.
Marinate in fridge 30 minutes (longer for extra flavor).
Salsa: Mix all ingredients in medium bowl. Refrigerate until ready to serve.
Transfer fish to grill and discard leftover marinade. Broil or grill over medium heat 5 to 6 minutes per side or until desired doneness. (Tuna is more moist when its center is still rosy-pink after cooking.)