Combine beans, onion, chili peppers, corn, tomato sauce, cumin, chili powder and taco seasoning in a slow cooker. Place chicken on top and cover. Cook on low for approximately 8 hours or on high for 6 hours. Check towards end time so as not to overcook.
Half hour before serving, remove chicken and shred. Return chicken to slow cooker and stir. Top with fresh cilantro.