Melt butter in saucepan over med- low heat. Stir flour; keep stirring until smooth and bubbly.

Remove from heat and add chicken broth and 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 enchilada sauce and chicken broth mixture. Gradually whisk in remaining milk until smooth, Set aside.

In a crock pot, combine beans, tomatoes, corn, onion, and bell pepper.

Place the chicken breasts on top of mixture.

Pour sauce mixture over ingredients in cooker.

Cover, cook on low for 6-8 hours or high 3-4 hours.

Remove chicken and cut or shred into bite sized pieces.