Twenty Quick Soups by Sarah Tyson Rorer

Wash and pull apart two good-sized heads of lettuce. Throw them into a hot saucepan, shake over the fire until the lettuce leaves simply melt. Sprinkle over a teaspoonful of salt, then press through a sieve. Put one quart of milk in a double boiler. Rub together two tablespoonfuls of butter and two of flour, add it to the milk and stir until it thickens. Chop sufficient parsley to make two tablespoonfuls and pound it in a mortar. Put this in a bowl; mix it with the lettuce that has been pressed through the sieve. Stir in the milk, then add a half teaspoonful of beef extract, dissolved in a little of the hot milk; season and serve.