Combine wine, vinegar, water, two-thirds of the sliced onions, carrots, shallots, peppercorns, six of the gloves, three of the bay leaves, 1 teaspoon of salt, mustard seeds, and parsley sprigs in a nonreactive saucepan. Broil to a boil, reduce the heat, and simmer for 5 minutes. Cool the marinade. Place the beef in a large nonreactive bowl, pour the marinade the roast in the refrigerator for four days. Turn the beef once a day to be sure the roast marinates evenly.
Remove the roast from the marinade and pat it dry with paper towels. Strain the marinade through a sieve into a bowl, pressing the vegetables with the back of a spoon to extract all of their liquid before discarding them. Set the marinade aside.
With a sieve, dust 2 tablespoons of flour over the roast, coating all sides. Heat the oil in a heavy 5- to 6- quart casserole. Add the beef and cook over moderate heat for about 20 minutes, or until it is well browned on all sides. Remove the roast from the casserole and pour off all the fat. Return the roast to the casserole, add the remained sliced onion, 6 cloves, 1 bay leaf, and 2 cups of the marinade. Bring the marinade to a boil over moderate heat, reduce the heat to low, cover the casserole, and simmer the beef for 3 hours.
In a small skillet, melt the butter over moderate heat. Stir in the suar and the remaining 3 tablespoons of flour, and cook over low heat, stirring constantly, until the mixture is a rich brown color. Pour the cooking liquid from the casserole; strain it and return it to the casserole. Stir the sugar-flour mixture into the cooking liquid. Cover the casserole and continue cooking over low heat until the roast is very tender- about 1 hour more.
To serve, transfer the roast to a heated platter. Stir the ginger-snap crumbs into the gravy remaining in the casserole. Using a whisk, cook, and stir for two or three minutes, until the gravy is smooth and thick. Taste it and add more salt and a few grindings of pepper if necessary.
Carve the meat into fairly thick slices and arrange them, overlapping the slices, on a heated platter. Spoon some of the gravy over the beef, and present the rest in a sauceboat.
Serving Size 6