On baking sheet, bake sweet potato until just tender (400ºF oven about 35-40 minutes. Do not overbake). Let it cool, then peel and discard skin. Cut into sticks. In a 9" skillet, combine margarine and oil. Heat until bubbly and hot. Add sticks and cook over medium heat, turning often with spatula, until crispy outside and tender inside. Serve sprinkled with brown sugar. Is good recipe doubled.