Heat oil in a large nonstick skillet over medium heat. Add onion, pepper, and salt; cook 5 minutes, stirring occasionally. Add broth; cook 5 minutes or until liquid evaporates. Stir in vinegar and sugar; cook 5 minutes. Add Blackened Grilled Flank Steak to pan; cook 3 minutes or until thoroughly heated. Set steak mixture aside; keep warm.
Mash beans with a fork until smooth. Warm tortillas according to package directions. Spread 1/4 cup beans over each tortilla, leaving a 1-inch border. Top each tortilla with 1 cup lettuce, 1/4 cup rice, and 2 tablespoons cheese. Divide steak mixture evenly among tortillas; roll up.