Heat oil in a large nonstick skillet over medium heat. Add chicken, onion, and garlic; cook 8 minutes or until chicken is done, stirring constantly. Stir in barbecue sauce and beans. Sprinkle with cheese; cook 5 minutes or until thoroughly heated. Warm tortillas according to package directions. Spoon about 1/2 cup chicken mixture down center of each tortilla; top each with 1 tablespoon sour cream, and roll up.