Place chicken breasts in the bottom of your slow cooker
Add chili powder, onion powder, cumin, garlic powder and cayenne
Top with beans, corn, chiles and finally, the chicken stock
Cook on low for 5 - 7 hours
Remove the chicken from the slow cooker and shred the chicken using 2 forks. Return the chicken to your slow cooker.
In a non-stick skillet, melt the butter. Sprinkle the flour over the butter and whisk to completely blend. Allow the butter/flour mixture to cook until is starts to brown. Slowly whisk in the milk and boullion, making sure all lumps are gone.
Allow this mixture to cook for about 5 minutes or until it starts to thicken.
Add the butter/flour/milk mixture to the crockpot and stir to combine
Add the sour cream.
Cook for another hour on low and serve!