How to Make It
Melt butter in a saucepan over medium-low heat. Stir in flour; keep stirring until smooth and bubbly. Remove from heat and add the chicken broth and ½ cup milk, a little at a time, stirring to keep smooth. Return to heat. Bring sauce to a gentle boil; cook, stirring constantly, until it thickens. In a large bowl, whisk together the enchilada sauce and chicken broth mixture . Gradually whisk in remaining milk until smooth. Set aside.
In a crockpot, combine drained beans, tomatoes, corn, onion, and bell pepper. Place the chicken breasts on top of the mixture. Pour sauce mixture over ingredients in cooker. Cover; cook on low heat for 6 to 8 hours or on high for 3 to 4 hours. When you are ready to serve, remove chicken and cut or shred into bite-sized pieces. Add chicken back into the soup, mix together. Top with cheese and serve. I topped ours with slices of avocado, sour cream, and crushed tortilla chips.