Coat the inside of the crock pot with cooking spray.
Place the chicken in the bottom of the crock pot, followed by the remaining ingredients – except the cheeses and fried onions.
Stir gently to combine; cover and cook on low for 5 - 6 hours or on high for 2 - 3 hours.
When chicken is cooked, add the shredded cheeses and fried onions; cover and cook for an additional 15 - 20 minutes or until the cheeses have melted.