Make this basic soup, then customize with chopped, cooked chicken or turkey, frozen thawed peas, small cooked pasta, cooked rice, sliced mushrooms, etc.
Sauté onion and celery in butter in a medium saucepan, over medium heat, about 1 minute or until tender.
Stir in corn starch until smooth. Add chicken broth and milk. Whisk continuously until mixture boils. Boil for 1 minute. Season with salt and pepper.