Shred the cabbage. Melt half the butter in a heavy pot; then add the cabbage and toss until covered with the butter. Add bacon stock or water, cover and cook gently for about 20 minutes. By this time the liquid should be nearly absorbed, and the cabbage cooked. Add the nutmeg or mace, the flour, and stir well; then add the rest of the butter and toss until melted into the cabbage. Add pepper if needed.