Mince the garlic and shallot in a mini food-processor.
Combine all ingredients: the chicken, beans, butter, garlic, parsley, shallot, lemon juice and zest, 2 tsp. salt and several grinds of black pepper in a 6-8 quart slow-cooker, AKA Crock Pot.
Cook on high for one hour stirring ingredients once to make sure they are well combined.
Reduce heat to low and cook for another 3 hours until chicken is very tender. Stir a couple more times during the last 3 hours of cooktime.
Break the chicken into large bite-sized pieces using two forks. Stir in the sour cream.
Serve topped with croutons and more parsley.
You may also serve with warm, crusty French bread.