Method:
Place oil, rosemary, and 1 clove of the garlic into a blender and puree until almost smooth. Add salt and pepper. Pour garlic mixture over the lamb, rubbing it into the surface of the meat. Cover and refrigerate for at least 2 hours. Preheat oven to 350°F. Arrange carrots, potatoes, and onions in the bottom of a roasting pan. Pour or spoon marinade that has dripped off the lamb onto the vegetables and toss well to coat. Season with salt and pepper. Cut small slits into the top, sides, and bottom of the lamb. Thinly slice the remaining clove of garlic and place a slice into each slit. Set the lamb in the pan with the vegetables and pour wine over the top.
Roast lamb and vegetables for 45 minutes, covered, and an additional 45 minutes, uncovered, or until lamb is done to your liking. Transfer lamb to a cutting board and let it sit for 20 minutes.
Meanwhile, check the vegetables. If they are not yet tender, cover and return to oven while lamb is resting to continue roasting until tender. Transfer lamb and vegetables to a serving platter and drizzle with pan juices.