Leave the potato skin on. Cut it vertically into half, then cut horizontally into ¼-inch thick slices. Try to slice them evenly so they are all equally thick. Brush both sides of each potato slice with olive oil. Spread them out in one layer on a baking sheet. Broil for 15 to 20 minutes or until done, turning, once. Mix Parmesan, onion and paprika, sprinkle evenly on the potato slices. Broil for 2 more minutes. Serve immediately.