Heat liquids: In a medium sized sauce pan, bring 2 cups water, 3 teaspoons bouillon and ½ cup of milk to a low simmer. You can also use canned chicken broth, if you prefer.
Whisk milk and flour: In a small bowl, whisk together the remaining ½ cup milk, ⅓ cup flour, ¼ teaspoon garlic powder, ¼ teaspoon onion powder, ¼ teaspoon celery salt and salt and pepper.
Cook: Whisk flour mixture into the sauce pan and continuously whisk for about 5 minutes, or until thick.
