Place the lamb, prosciutto or bacon, onion, and lard in a 2 quart casserole and brown thoroughly over low heat. Add salt and pepper, sprinkle with flour and stir well. Add wine and cook until it evaporates. Add water to cover meat and cook 45 minutes or until meat is tender, adding more water if needed. Beat egg yolks and lemon juice together. Add parsley and marjoram and mix well. Lower heat as mush as possible and pour egg mixture over meat. Mix well, turn off heat and let stand on range 5 minutes before serving. Serves 4