the lamb with the marinade, basting it frequently, in a warm oven 325 deg F until done. About 10 minutes before the meat is cooked, pour off the marinade and meat juices into a saucepan. Reduce the gravy to half its original quantity by boiling vigorously. Carve the meat into thin slices and add the resulting juices to the marinade. Arrange the meat on a serving dish and keep warm. Remove the gravy from the heat, stir in cream and carefully reheat the sauce until it forms a medium-thick consistency. Pour the sauce over the lamb and keep warm.