Preheat oven to moderate 180°C (350°F). Trim lamb of excess fat and sinew.
To make Stuffing: In a small bowl, combine the breadcrumbs, onion, garlic, parsley, egg and rind. Press stuffing mixture into cavity of the lamb.
Tuck in ends of lamb to enclose stuffing. Tie lamb securely with string at regular intervals to retain shape during cooking. Place oil in a deep baking dish and add the prepared lamb. Bake 1-1¼ hours for rare meat, 1¼-1½ hours for medium, or 1½-1¾ hours for well-done. Remove lamb from pan, and leave, covered, for 10-15 minutes before slicing.
To make Gravy: Drain all except ¼ cup of pan juices from baking dish. In a small jug, blend flour, Worcestershire sauce and stock, stirring until smooth. Add to juices in dish, stir over medium heat 3 minutes or until the gravy boils and thickens; strain. Serve with sliced lamb.
