This recipe is suitable for anyone who needs to know the exact contents of soup. Other Options: Regular recipes use about 1 1/2 Tb butter and 1 1/2 Tb flour per cup of milk for a medium white sauce.
5 oz evaporated milk plus 5 oz water plus 1 Tb corn starch
1 cup soy milk plus 1 Tb corn starch
1 cup skim milk plus 1 Tb vegetable oil plus 1 Tb corn starch
Put ingredients in a blender and process at high speed until well blended, or put ingredients in a jar and shake, or stir dry ingredients into cold milk with a whisk.
Stir constantly in the top of a double boiler until the sauce thickens and simmers, then cook ten minutes. A medium saucepan set in a larger saucepan of simmering water works, too.
Fresh tomatoes may be cooked with onion and seasoning, allowed to cool and pureed in a blender to make the sauce. If the tomato mixture is colder, add a little of the hot white sauce to bring it to the same temperature. This prevents curdling when the red mixture is gradually added back into the pot with the white sauce.
Heat soup until it is hot enough to serve but do not allow it to boil.
The same method may be used with 3/4 to 1 cup of cooked diced (or pureed) vegetables with cooking liquid used to make the sauce. Makes about 2 cups. Suggested vegetables: potato with a little onion, carrot, zucchini, cabbage with a little ham, sauteed onion, mushroom, broccoli. Season to taste.
Tested Dec 93 using powdered milk, and (thawed) canned tomato by Elizabeth Rodier. This was a successful experiment based on a combination of recipes from several different books.