Zest limes; reserving zest for later. Juice limes.
Combine tequila, lime juice, garlic and 3 tablespoons olive oil (2 tablespoons will be used later). Marinate steak in a zipper-locking plastic bag 2 to 4 hours in refrigerator.
Preheat grill to high. Remove steak from marinade, discard marinade. Season steak with salt and pepper. Grill or broil steak to desired doneness. Let steak rest 5 minutes and slice thinly across the grain.
Grill jalapeños flesh side down until charred and slightly soft; mince and combine with beef.5 Wrap tortillas in foil and place on top shelf of closed grill to warm.
Combine tomatoes/avocados, reserved lime zest and Triple Sec. Heat remaining olive oil in large sauté pan. Turn off heat, add tomato mixture and toss gently. Add beef mixture and cilantro; toss gently to combine. Add salt and pepper to taste and serve immediately with warm tortillas.
Recipe and photo courtesy of Certified Angus Beef.