Sweet Potato Shepherd's Pie

1. Scrub and pierce sweet potato; place on a microwave-safe plate. Microwave, uncovered, on high for 10-12 minutes or until tender, turning once. 2. Meanwhile, in a large skillet, cook beef and onion until meat is no longer pink; drain. Add the corn, tomato sauce and spices. Place in a 1-qt. baking dish coated with cooking spray; set aside. 3. When cool enough to handle, cut potato in half; scoop out the pulp and place in a small bowl. Mash with butter, milk, salt and pepper. Spread evenly over meat mixture. 4. Bake, uncovered, at 350° for 25-30 minutes or until heated through.