Potato Soup

9 medium potatoes, peeled and diced
3 carrots, diced
9 celery ribs, diced
3 quarts water
1 onion, chopped
1/2 cup butter (1 stick)
1/2 cup flour
1 1/2 teaspoons salt
1 teaspoon pepper
3 cups milk

In a large kettle, cook potatoes, carrots and celery in water until tender, about 20 minutes. Drain, reserving liquid and setting vegetables aside. In the same kettle, saute onion in butter until soft. Stir in flour, salt and pepper; gradually add milk, stirring constantly until thickened. Gently stir in cooked vegetables, mashing potatoes if necessary. Gradually add reserved cooking liquid, 1 cup at a time, until soup is desired consistency.

Makes 12-15 servings.