The sauce in Chicken Pot Pie Soup is typically a creamy and savory mixture made from scratch. It's usually created using a combination of butter, flour (for thickening), chicken broth, and heavy cream or milk. This mixture forms the base of the soup, creating a luscious and velvety texture that coats the chicken and vegetables. Herbs, seasonings, and sometimes a touch of white wine may also be added to enhance the flavor profile of the sauce.