In large soup pot, combine ham base, ham, carrots, celery and onions in water and cook over medium heat 15 minutes. Add potatoes and cook until tender, 15 to 20 minutes. Combine milk and cheese spread in a small saucepan. Cook over low heat, stirring until mixture is combined and warmed through. Add to potato mixture. If desired, thicken soup by gradually adding the flour/water mixture until soup has reached desired consistency. When thickened, remove from heat and add salt and pepper. Makes about 10 servings.