Cut a thin slice from top and bottom of onion and tomato; discard. Cut onion and tomato into 2 slices.
Grill onion, steaks, and peppers, covered with grill lid, over medium-high heat (350° to 400°) 10 minutes, turning after 7 minutes. Add tomato, and grill, turning occasionally, 3 minutes. Add tortillas, and grill 1 minute on each side or until crisp. Remove vegetables and tortillas; remove steaks (medium-rare), or continue grilling to desired degree of doneness.
Place tortillas on individual serving plates; top evenly with peppers, tomato, Burgundy Mole Sauce, steaks, and onion. Serve with Sweet Salsa and Pico de Gallo, and garnish, if desired.