HEAT grill for indirect grilling: Light one side of grill, leaving other side unlit. Close lid; heat grill to 375ºF.
COMBINE first 4 ingredients. Reserve 1/2 cup cheese mixture; stir remaining into bean mixture.
BRUSH pepper halves with oil; fill with bean mixture. Top with reserved cheese mixture.
COVER grill grate (over unlit burner) with foil. Place peppers on foil; cover grill with lid. Grill 25 to 30 min. or until peppers are tender and filling is heated through, monitoring for consistent grill temperature and rearranging peppers occasionally to prevent burning.