(Recipe #64, page 91)
Prepare some crayfish butter, reserving the cooked tails, and make the fricassee as described above, but ¼ hour before serving instead of the additions listed add morels, mace, and a roux of butter and flour. Remove all the fat from the sauce and just before pouring it over the meat heat it with a generous amount of the crayfish butter. When serving add the crayfish tails to the sauce along with (optionally) 1–2 egg yolks.
Translated by David Green.