Sauce Périgueux

Ingredients

• 500 ml demi-glace, reduced espagnole to half volume
• 150 ml dry Madeira, Sercial or equivalent dry style
• 50 g fresh black truffle, Tuber melanosporum; cut in brunoise, 2–3 mm dice
• 30 ml truffle juice, liquid from canned Périgord truffles, or juice released during preparation; approximately 2 tablespoons
• 30 g unsalted butter, cold, cut into small cubes

Method

1. 1
   Pour the demi-glace into a wide saucepan and reduce over medium heat by one-third, skimming as necessary. The sauce is ready when it coats the back of a spoon with a dark, lacquered film.
2. 2
   In a separate pan, reduce the dry Madeira by half over medium heat, concentrating its oxidative, nutty character. The liquid should smell of roasted nuts with no raw alcohol on the nose.
3. 3
   Combine the reduced demi-glace and the reduced Madeira in one pan and bring to a gentle simmer. Add half the truffle brunoise (25 g) and all the truffle juice. This is where the dish lives or dies: the truffle may remain in contact with the heat for no more than 5 minutes in total — prolonged heat dissipates the volatile aromatics that define the sauce entirely. After 4 minutes, add the remaining 25 g of truffle brunoise off or at the edge of the heat so that the final addition perfumes without cooking.
4. 4
   Remove the pan from the heat. Add the cold butter cubes and mount the sauce by swirling and tilting the pan steadily until every cube is absorbed. The sauce is done when it is dark, glossy, and visibly full-bodied, with truffle pieces suspended throughout rather than settled.