Step 1

To a 6 qt slow cooker, add the first 8 ingredients (potatoes through and including chicken stock).  Stir, cover, and cook on LOW for 8-10 hours, until potatoes are tender.

Step 2

In a small mixing bowl, whisk milk and cornstarch until smooth.  Stir into soup in slow cooker, cover and cook on HIGH 20-25 minutes until thickened, stirring occasionally.  Turn off heat, stir in cheese, sour cream and parsley until cheese is melted.

Step 3

Serve sprinkled with extra cheese, black pepper and parsley if desired.