This section is from the book "Mrs. Rorer's Vegetable Cookery And Meat Substitutes", by Sarah Tyson Rorer. Also available from Amazon: Mrs. Rorer's Vegetable Cookery And Meat Substitutes.......
1/2 pound mushrooms (Ag aricus campestris)
1 tablespoonful cornstarch
2 tablespoonfuls butter
1 quart milk
1 teaspoonful salt
1 saltspoonful pepper
Wash the mushrooms but do not peel them; cut into thin slices, using all the good portion of the stem; put them, with the butter and salt, into a saucepan; cover closely and cook slowly twenty minutes. Add the milk and pepper. Moisten the cornstarch with a little cold milk; stir it into the hot mixture and cook slowly until the soup is the consistency of thick cream. Serve at once, ladling it over squares of toast, or pass with it whole wheat bread.