This is a most wholesome soup, which would be popular in America if it were better known. It is much used in France, Sorrel can be obtained, in season, at all the French markets in America.
For four quarts of soup, put into a saucepan a piece of butter the size of an egg, two or three sprigs of parsley, two or three leaves of lettuce, one onion, and a pint of sorrel (all finely chopped), a little nutmeg, pepper, and salt. Cover, and let them cook or sweat ten minutes; then add about two table-spoonfuls of flour. Mix well, and gradually add three quarts of boiling water (stock would be better). Make a liaison, i. e., beat the yolks of four eggs (one egg to a quart of soup), and mix with them a cupful of cream or rich milk.
Add a little chevril (if you have it) to the soup; let it boil ten minutes; then stir in the eggs, or liaison, when the soup is quite ready.