1 - In a 3½- to 6-quart slow cooker place the onion, garlic, cumin, oregano, red pepper, beans, 2 cans chile peppers, broth, and cooked chicken. Stir to combine.
2 - Cover and cook on low heat setting for 7 to 8 hours or on high-heat setting for 3½ to 4 hours. Stir in the cheese until melted.
3 - Ladle the chili into 8 bowls. If desired, top with sour cream and sprinkle with additional chile peppers.