1. Combine marinade ingredients in small bowl. Place beef steaks and marinade in food-safe plastic bag; turn steaks to coat. Close bag securely and marinate in refrigerator 15 min to 2 hours.
2. Remove steaks from marinade; discard marinade. Place steaks on grill over medium, ash-covered coals. Grill, covered, 10 to 14 min for medium rare to medium doneness, turning once. Meanwhile combine avocado salsa ingredients in medium bowl. Set aside. Place tortillas on grill. Grill until warm and slightly charred. Remove and keep warm.
3. Carve steaks into slices. Serve in tortillas with avocado salsa. Top with onion, cilantro and lime wedges, as desired. Serves 6.
Note: One beef flank steak (about 1-1/2 to 2 lbs) or 1-1/2 pounds skirt steak (cut in 4 to 6 inch portions) may be substituted for blade steaks. Increase marinating time to 6 hours or overnight. Grill flank steak, uncovered, 17 to 21 minutes (skirt steak 10 to 13 min) for medium rare doneness, turning once.
$5000 winner, 2005 National Beef Cook-Off