Potato Ham Soup

3 1/2 cups peeled and diced potatoes
1/3 cup diced celery
1/3 cup finely chopped onion
3/4 cup diced cooked ham
3 1/4 cups water
2 tablespoons chicken bouillon granules
1/2 teaspoon salt, or to taste
1/2-1 teaspoon ground white or black pepper
5 tablespoons butter
5 tablespoons flour

• Combine the potatoes, celery, onion and water in a stockpot. Bring to a boil, then cook over medium heat until potatoes are tender, about 10 to 15 minutes. Stir in the chicken bouillon, salt and pepper.
• In a separate saucepan, melt butter over medium-low heat. Whisk in flour with a fork, and cook, stirring constantly until thick, about 1 minute. Slowly stir in milk as not to allow lumps to form until all of the milk has been added. Continue stirring over medium-low heat until thick, 4 to 5 minutes.
• Stir the milk mixture into the stockpot, add ham and cook soup until heated through. Serve immediately.