Cut the turnips into very long, thin slices. Place the turnips in a frying pan with butter and sugar. Prepare a round mold of about 3 inches in diameter. Cut the foie gras, place it in a pan, and let it lightly smoke and cook a few seconds on each side. Place the turnip mixture, then the foie gras in the mold. Place the puff pastry circle on top of this. Bake in a 392 degree F. oven for 6 to 7 minutes. Remove the pastry circle from the mold and put it on a grill to let it cool. For the sauce, reduce the port wine with sugar, cinnamon, and vanilla. Place the tatin or tart in the middle of the serving dish, IMCOMPLETE