Place steak and 1/2 cup Herdez® Casera Salsa in a food-safe plastic bag; turn steak to coat. Close bag securely and marinate in the refrigerator for 1 hour.
Remove steak from marinade; discard marinade. Place steak on grid over medium, ash-covered coals, or cook in a pan. Grill (or cook in pan), covered, 7 to 10 minutes (over medium heat on a preheated gas grill, covered, 7 to 10 minutes) for medium-rare (145°F) to medium (160°F) doneness, turning occasionally.
Remove; let stand 5 minutes. Cut steaks lengthwise in thirds, then crosswise into 1/4-inch thick pieces.
Spread each tortilla with 1/4 cup of refried beans. Top with lettuce, beef, and the remaining 3/4 cup salsa. Sprinkle with cheese and onion.