Put all of the ingredients except the sour cream and half + half in the slow cooker.
Cook on low for 6-8 hours or high for 4-6 hours.
Remove chicken and chop into bite sized pieces. Return to the slow cooker.
Stir in the sour cream and half + half and serve.
Notes
This recipe works best with full fat sour cream.If you don't have half and half, milk or cream will work in a pinch.Feel free to adjust the amount of heat to your preferences. Reduce the amount of chilies and cayenne for a milder soup. Use the hot cans of chilies or switch to jalapenos for more spice. Use whatever white beans you have on hand. Navy beans, great norther, or cannellini, even chickpeas work.