Combine the potatoes, cauliflower, onion, celery, carrot, broth, parsley, salt and pepper in a crock pot.
Cover and cook on LOW 7 to 9 hours, or until the potatoes are tender.
Stir in the evaporated milk during the last hour.
Enjoy as is or if you like your soup creamy you can puree it using a stick blender or potato masher right in the crock pot. Or you can puree all or part of the soup with a traditional blender. Do this carefully in small batches so you don't burn yourself.