HEAT barbecue to medium-high heat.
GRILL steak 4 to 5 min. on each side or until medium doneness, brushing with barbecue sauce for the last minute. Remove from barbecue; cover loosely with foil. Let stand 5 min. Meanwhile, grill tortillas 15 to 30 sec. on each side or just until warmed.
COMBINE remaining ingredients.
CUT steak across the grain into thin slices. Serve with tortillas and bean mixture.
serving size = 2 fajitas (385 g)