Delicious Ham and Potato Soup

INGREDIENTS

• 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 teaspoon ground white or black pepper, or to taste
• 5 tablespoons butter
• 5 tablespoons all-purpose flour
• 2 cups milk