When the potatoes are drained, remove the hot baking sheets from the oven. Pour 2 tablespoons of olive oil onto the baking sheet. Spread onions and potatoes onto the hot oil and mix well, making sure the potatoes are coated in oil. Add more oil if needed to coat the potatoes. Sprinkle with salt and cayenne pepper, and place in oven. Cook approximately 45 minutes, stirring 3 or 4 times during the cooking process to ensure even cooking. Remove potatoes when they are nicely browned. Feel free to turn on the broiler for the last 5 minutes for even more browning. Remove from oven and add more salt and pepper to taste. Serve immediately. Yum!