Pierce the potatoes all over with a for. Microwave the potato until tender, turning once, about 12 minutes. While hot, cut the potatoes in half and score the flesh to allow the steam to escape. When still warm but cool enough to handle scoop the flesh into a ricer* and rice into a medium bowl. Spread evenly in the bowl to continue to allow the steam to escape. Discard the skin. Add the salt, pepper and flour and gently toss to combine. Form a well and add the egg. Using your hand and starting in the center, mix well to combine. Place the dough onto a clean counter dusted with flour. Knead the dough just until blended, about 4 or 5 times.