Brouet de Verjus et de Poulaille

From Le ménagier de Paris (Paris, 1393; recipe from 1846 edition): (For summer.) Take a quartered chicken, or veal, or baby chickens and cook in broth or other liquid with bacon, wine, and verjuice, so that the flavor of verjuice mellows: then fry your meat in good lard, and have egg yolks and Poudre Fine beaten together and work them through a tamis sieve; then trickle your eggs into your pot of broth very slowly, and stir rapidly with a spoon while the pot is on low heat: then have parsley sprigs and juice from boiled meat or meat broth, stirred with the spoon into the pot on low heat, or alternatively cooked in another small pot in fresh water to extract the first green; then present your meat, and coat it with your cooking broth, then with your green parsley.