Add chicken, 3 cups broth, cumin, garlic powder, onion salt, cream cheese, black beans, corn, enchilada sauce, and tomato sauce to your slow cooker. Cover and cook on high for 3-4 hours or on low 7-8 hours.
About 10-15 minutes before serving, shred the chicken with 2 forks and stir soup until cream cheese is combined with soup. Whisk remaining 1/3 cup chicken broth (or water) and flour (or masa harina). Add to slow cooker and stir until thickened. Serve warm with additional toppings as desired.
Enchilada sauce: I like to use 2 10-ounce cans of mild and 1 10-ounce of medium instead of one large can.