Thick Potato Soup

5 or 6 potatoes - diced
1 large onion - diced
1 or 2 stalks of celery - diced

1/2 cup butter
3/4 cup flour
1 1/2 tsp salt
1 1/2 tsp pepper

6 cup milk

Boil first three ingredients in just enough water to
cover until fork tender. Make a roux from the butter
and flour. Add milk, salt, and pepper. Cook until
thickened and add to vegetables and water.
Bring to simmer and serve warm