Jus Lié — Lightly Thickened Meat Jus

Ingredients

• 1 litre brown stock or roasting jus, well-reduced, strong
• 10 g arrowroot, or cornstarch for banquet service
• 30 ml cold water, for dissolving the starch
• 20 g cold unsalted butter, cut into small pieces

Method

1. 1
   Bring the well-reduced brown stock or roasting jus to a steady simmer in a saucepan over medium heat. The surface should tremble evenly; a rolling boil will cloud the jus before thickening begins.
2. 2
   In a separate small vessel, dissolve the arrowroot completely in the cold water. The slurry must be fully smooth and free of dry pockets before it approaches the jus — arrowroot added dry or to hot liquid lumps instantly and cannot be recovered.
3. 3
   Whisk the cold slurry into the simmering jus in a thin, steady stream. The jus thickens almost immediately. This is where the dish lives or dies: stop the moment the jus achieves a light veil — it should pool on a plate and move like liquid silk, dark and translucent, with the faintest perceptible body. If it coats the back of a spoon like a sauce, it is already too thick and cannot be corrected by further cooking.
4. 4
   Pass the thickened jus immediately through a fine chinois — or through muslin for the most refined finish — into a clean pan. The strained jus should appear dark, clear, and brilliant, with no cloudiness or starchy opacity.
5. 5
   Remove the pan from the heat. Swirl in the cold butter piece by piece. The jus is ready when it carries a perceptible sheen but remains entirely unburdened — it should not register as an enriched butter sauce on the palate.