Potato-Cheese Soup
["2 potatoes, sliced thinly", "1 to 2 stalks celery, chopped", "1/2 large onion, chopped", "1 3/4 c. boiling water", "1/4 c. margarine", "2 1/2 Tbsp. flour", "1 1/8 tsp. A. 1. sauce", "1/2 tsp. mustard powder", "1 1/2 c. milk", "6 oz. sharp Cheddar cheese", "1 (16 oz.) can tomatoes", "pinch of parsley or dill weed"]
["Cook vegetables in boiling water until soft.", "Set aside."]
["potatoes", "stalks celery", "onion", "boiling water", "margarine", "flour", "A.", "mustard powder", "milk", "Cheddar cheese", "tomatoes", "parsley"]