Important - Do not use baking potatoes. Use only thin skin white or Red Bliss. Mince leeks and onion finely. Saute leeks and onion in butter in a large soup pot until soft. Slice potatoes very thin. Add sliced potatoes and chicken stock to soup pot and cook over medium high heat until potatoes are fully cooked and soft. Approx. 30 minutes. Let mixture cool Puree potatoe and broth mixture in a food processor or blender in batches until smooth. Return to soup pot add milk and cream and bring to a boil. Serve and enjoy.
This recipe makes about 8 quarts of soup. Don't worry though, this soup freezes exceptionally well.