Add 1 tablespoon (15 milliliters) gastrique to 1¼ cups (300 milliliters) demi-glace and 5 fluid ounces (150 milliliters) game stock. Reduce the sauce by one-fourth or until syrupy, and strain it through a fine chinois. Finish with 1 tablespoon (15 milliliters) dark raisins, plumped, and 1 tablespoon (15 milliliters) white raisins, plumped. (Soak each type of raisin in 1 tablespoon [15 milliliters] warm water for 20 minutes to plump and soften them before adding to the sauce.) Lightly toast 1 tablespoon (15 milliliters) pine nuts in the oven and add them to the sauce.