Sweat the mirepoix and add the trimmings as described for the classic method. Gently cook the mirepoix with the trimmings until the juices on the bottom of the pan begin to caramelize. Add 6 tablespoons (90 milliliters) white wine to the pan and continue reducing until all the liquid evaporates, leaving a brown layer of caramelized juices on the bottom of the pan. (The steam generated by the reducing wine causes the trimmings to release their juices, which should then caramelize on the bottom of the pan.) When the wine has been completely reduced, add ½ cup (125 milliliters) brown beef or chicken stock, and again reduce until no liquid remains, gently scraping the bottom of the pot with a wooden spoon or spatula while the stock is reducing, so that the caramelized juices dissolve. When the stock has reduced and formed a thick caramelized glaze on the bottom of the pot, add 6 tablespoons (90 milliliters) white wine and cook it just long enough to scrape up and dissolve the caramelized juices. Add 1¾ cups (450 milliliters) brown beef or chicken stock (or game stock, if available), and simmer for 45 minutes. Strain into a clean saucepan through a coarse chinois. Stir enough glace de viande into the sauce to give it the consistency of a light syrup and to reinforce its color—usually about ¼ cup (60 milliliters) glace de viande is needed. Whisk 2 ounces (60 grams) butter into the sauce. Strain through a fine chinois.