Lemon Soup
(France.) This is a very dainty soup and deserves to be better known. Heat 1 1/2 quarts of chicken stock and make some forcemeat balls of a little cold chopped chicken, bread-crumbs, herbs, and yolk of an egg. Poach them in the stock and keep warm. Now thicken the stock with 1/2 cup of milk or cream, mixed with the yolks of 3 eggs, salt, and pepper, the juice of a lemon and a pinch of nutmeg. Serve with slices of toast. A convent recipe, dating to the days before the Revolution.
An egg-and-lemon liaison thickens this soup, so the whole dish turns on temperature control rather than any difficult technique.
- The hinge: never let it boilOnce the yolks and cream go in, the stock must stay below a simmer — around 160-170F. Whisk a ladleful of hot stock into the egg mixture first, return it to the pan off the heat, and warm it gently until it coats a spoon. A boil will scramble the yolks into threads.
- Add the lemon lastAcid and heat together curdle dairy quickly. Stir the lemon juice in after the soup has thickened and been pulled from the heat, and taste before adding all of it; lemons vary a good deal in size and juiciness.
- Quantities and yield1 1/2 quarts is 6 cups, serving four to six as a first course. Half a cup of cream is a light thickening — use heavy cream if you want more body, milk if you want the soup closer to a broth.
- Forcemeat ballsAim for marble size, about 3/4 inch. Bind roughly 1 cup finely chopped cooked chicken with 1/3 cup fresh crumbs, one yolk, and chopped parsley, tarragon or chervil. They need only 3-4 minutes at a bare simmer; longer and they tighten and go dry.
- Poach them separately if you canThe crumbs will cloud the stock. Poaching the balls in a little stock in a second pan, then lifting them into the finished soup, keeps it clear.
- Cold chickenThe recipe assumes cooked chicken left over from a previous meal. Poached thigh meat works better than breast here, staying moist in the small dumplings.
- The toastServe it dry and thin alongside rather than floating in the bowl, where it dissolves into the thickened stock within a minute or two.
Egg-and-lemon thickened broths run right across the old Mediterranean and Near East — Greek avgolemono, Turkish terbiyeli soups, and the French liaison à l'oeuf all rest on the same trick of using yolk as a thickener where flour would be coarse. The convent attribution the author gives is the sort of provenance that travelled by word of mouth and is generally impossible to document, but it is plausible in outline: French religious houses before 1789 ran substantial kitchens, and are often said to have kept manuscript receipt books and to have practised a delicate invalid and fast-day cookery of roughly this kind, where a light broth enriched with egg was nourishing without being meat-heavy. With a Saucepan Over the Sea collected dishes country by country for American home cooks, and a soup like this one — cheap, made from a carcass and yesterday's chicken, but presentable at a dinner table — sits comfortably with the case such a book makes for foreign cookery.