Creamy Potato Soup

7 medium potatoes, peeled and chopped
2 celery ribs, diced
1 medium onion, chopped
4-cups chicken broth (4-cups water, 4-tsp chicken bouillon)   
1/4-cup butter
1/4-cup flour
2-tsp salt
1/2-tsp pepper
4-cups milk

In Dutch oven, combine potatoes, celery, onion, and water/bouillon
Boil for 20-25 minutes
Puree
In another pot, melt butter
Stir in flour, salt, and pepper
Add milk slowly and bring to a boil
Add to potato puree and heat through