Preheat the oven to 425 degrees. In a roasting pan large enough to hold the venison racks without crowding them, toss the shallots with 2 tablespoons of the oil and salt and pepper to taste and roast them in the middle of the oven, stirring occasionally, for 25 to 30 minutes, or until they are golden. Pat the venison dry, season it with salt and pepper, and rub it generously with the additional oil. Push the shallots to the sides of the roasting pan, stand the venison crown in the middle of the pan. Mound stuffing in center of roast in the middle of the oven for 25 to 30 minutes, or until a meat thermometer registers 125 degrees, for rare meat. Transfer the racks with shallots to a planter and let them stand, covered loosely with foil, for 15 minutes. To the roasting pan add the broth, the wine, the water and the juniper berries and simmer the mixture, scraping up the brown bits, for 5 minutes. Strain the mixture through a fine sieve set over a small saucepan, whisk the cornstarch mixture, and add it to the saucepan with the cranberries, the vinegar and salt and pepper to taste. Simmer the gravy, whisking for 5 minutes. Cut the venison into individual chops and serve it with the shallots and the gravy.