This is an excerpt from Le Viandier de Taillevent
(France, ca. 1380 - James Prescott, trans.)
The original source can be found at
James Prescott's website
White capon soup. Cook them in wine and water, dismember them, and fry them in lard. Crush almonds with some capon livers and dark meat, steep in your broth, and put to boil on your meat. Take ginger, cloves, galingale, long pepper and grains_of_paradise, and steep in vinegar. Boil well together, and thread in well beaten egg yolks. It should be well thickened.