Meanwhile, place potatoes, shallots, oil, salt and pepper in a large bowl; toss to coat. Place two 24-inch-long pieces of foil on the counter and lightly coat with nonstick cooking spray. Arrange potatoes and shallots in a single layer, slightly overlapping, on half of each piece of foil. Leave a 2-inch border on all sides. Fold foil over and pinch the edges together, making two packets.