Place lamb, garlic, rosemary, and olive oil in large bowl and mix well. Cover and refrigerate for at least 1 hour and up to 3. Preheat oven to 375˚. Remove lamb from bowl and wipe off as much of marinade as possible. Heat large sauté pan on medium-high, and season lamb with salt and pepper. Sear on both sides, about 3 minutes per side.

Remove lamb from pan, place on nonstick baking sheet, and put in oven. Remove all but 1 tablespoon of remaining oil and fat from pan. Reduce heat to medium and add shallots. Sauté for 3 minutes then add wine. When ¾ of liquid has reduced, add beef stock and preserves. When mixture has reduced by half and is a thick consistency, shut off heat.

When meat registers 125˚ on thermometer, remove from oven and allow meat to rest 7 to 10 minutes. Add remaining juices from lamb to sauce and stir well. Slice lamb, drizzle with sauce, and serve.