Potage Germiny

Potage Germiny (sorrel soup bound with egg yolks and cream) teaches the most delicate liaison, the binding of hot liquid with yolks. One true thing decides it: once the liaison enters the saucepan, the soup may approach the simmer, but it must never boil. The yolks should thicken like crème anglaise, giving body without announcing themselves as egg.

The original method assumed a saucier watching the pan, white consommé waiting beside a stockpot that never went cold, and service timed to the minute. At home, one heavy saucepan, a wooden spoon, and an instant-read thermometer do the same work. The separate hands and holding pans were brigade scaffolding and can go; the finished consommé, butter-melted sorrel, last-minute liaison, and cold-butter finish are the dish and must stay. The source proportions are retained in a home batch of about two quarts. One cook, one stove, one evening.

When it lands correctly, the soup is pale green and glossy, sharpened by sorrel but rounded by cream and butter, with fine chervil pluches floating at the surface. Stir continuously through the final thickening and pull the pan at the first tremor around its edge. Those few minutes decide everything.