The recipe hereafter is the one served at La Tour d’Argent (The Silver Tower) for about a century now. They give you a certificate for every half duck, mine was already in the 7 figures. It is not a modern recipe, the blood taste is quite strong and frankly, is not the best way to serve duck. But how spectacular!
Roast a duck to medium rare. Remove the skin.
The duck is liquified in a kitchen mixer, then put on a large metallic dish placed on a flame. The large surface will speed up the evaporation needed to concentrate the sauce.
The duck’s carcass is put in the press and crushed until the juice from the organs runs into the dish. How bloody. They do this on a pedestal right in the restaurant.
(Thank Markus for this one)