Pour milk into crock pot, set to high. Chop celery and onion finely and add. Add all other ingredients except potato flakes and potatoes. Bake potatoes at 350 for 1 hour and then coarsely chop. Add to crock pot along with potato flakes and stir thoroughly. Allow to simmer in crock pot for at least 2 more hours, stirring occasionally. Set to warm and serve as desired.