Have butcher bone, butterfly and pound the lamb to an even thickness. Make the marinade; in a large ceramic dish combine the wine, oil, onions, carrot, thyme, parsley, bay leaves, garlic, salt and pepper. Add the lamb, and let it marinate, covered and chilled, turning it occasionally, for 1-2 days. Drain the lamb, pat it dry and fit it into a grill basket which will keep it flat while cooking. Broil the lamb under a preheated broiler 3 inches from the heat for 10 minutes on each side for medium-rare meat, or until a meat thermometer registers 140 degrees. Transfer the lamb to a cutting board, let it stand for 10 minutes and carve it diagonally. Arrange the slices on a heated platter.