Ham and Potato Soup

5 cups peeled potatoes, cubed
1/2 cup celery, chopped
1/2 cup onion, diced
1 1/2 cups ham, chopped
5 cups water
1/8 cup chicken bullion (about 6 cubes)
1 tsp salt
Add all above ingredients (minus the bullion) and bring to a boil. Boil for 20 minutes. Stir in bullion.
Make roux and slowly stir into soup.
1/2 cup butter
1/2 cup flour
3 cups milk
melt butter add in flour. slowly pour in milk and whisk while pouring so it does not get lumpy. Cook 4-5 minutes before adding to soup.