Pour off most of the fat from the roasting pan. Add garlic, and place pan over medium heat. Cook for 1 minute, stirring. Pour in the stock and scrape up any brown bits from the bottom of the pan. Pour the contents of the pan into a small saucepan. Add the wine, maple syrup, and vanilla and cook over medium-high heat, stirring often, until the flavors are concentrated and the sauce starts to become syrupy. Taste for salt and pepper and stir in optional butter if you want a silkier sauce.
Recipe Courtesy of The Complete Meat Cookbook