In a 3-quart slow cooker, combine chicken, beans, tomatoes, peppers, onion and seasonings. Cover and cook on low for 5-6 hours or until chicken is tender.
Remove chicken and cool slightly. Shred and return to slow cooker to heat through.
Spoon about 3/4 cup chicken mixture down the center of each tortilla. Top with lettuce, tomato and& sour cream if desired