In a small bowl, combine the salt, pepper, rosemary, oil and garlic and stir until blended. Coat the lamb evenly with the mixture, wrap tightly with plastic wrap, and refrigerate for at least 4 hours or up to overnight.

Let the lamb stand at room temperature for 45 minutes to 1 hour.

Position a rack in the lower third of an oven and preheat to 425°F.

Set the lamb on a rack in a large roasting pan and roast for 15 minutes. Using a pair of large tongs, turn the lamb over, carefully add the wine to the pan and roast for 15 minutes more. Reduce the heat to 350°F. Continue roasting, turning the lamb every 20 minutes and basting occasionally with the pan juices, until an instant-read thermometer inserted into the center of the meat registers 125° to 130°F for very rare to medium-rare, about 1 hour more, or until done to your liking. Transfer the lamb to a carving board, cover loosely with aluminum foil and let rest for 10 minutes before carving.

Meanwhile, pour any juices from the pan into a bowl. Skim off the fat, reserving 2 Tbs., and set the pan over medium-high heat. Add the reserved fat and the shallots and cook, stirring to scrape up any browned bits stuck to the pan bottom, until the shallots are tender, 2 to 3 minutes. Add the stock and the reserved pan juices, bring to a boil and cook, stirring, until the liquid is reduced by half, 3 to 4 minutes more. Transfer the sauce to a warmed sauceboat.

Remove the twine from the lamb, carve into thin slices and transfer to a warmed serving platter. Pass the sauce alongside. Serves 6 to 8.