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.......
2 quarts spinach
1 quart milk
2 tablespoonfuls butter
2 tablespoonfuls flour
1 teaspoonful salt
1 saltspoonful pepper
Cut the leaves from the spinach; wash thoroughly through several cold waters, each time lifting them up with the hand and throwing them in another pan of cold water. Put a good-sized kettle on the fire; when hot, throw in the spinach; cover and push it at once over a slow fire. Let it stand for fifteen minutes until the spinach is thoroughly wilted. Drain, saving the water that has exuded from the spinach.
Chop the spinach very fine, then press it through a sieve. Put the milk in a double boiler; add the butter and flour, rubbed together; stir until you have a perfectly smooth creamy mixture; then add the spinach pulp and water, salt, pepper and onion. When very hot, serve. Lettuce or endive may be substituted for spinach, using two large heads.