Preheat the oven to 425 degrees F. Cook the potatoes in lightly salted boiling water until they are easily pierced with a knife. Drain them, mash a quarter of them into a bowl, cut the remainder into small cubes and reserve. To make the dough, dissolve the yeast in 1 cup warm water. Combine with 1/4 cup of the olive oil, salt, and the mashed potatoes. Stir in the flour a little at a time, adding just enough to make a dough that does not stick to the sides of the bowl. Knead the dough for 4 to 5 minutes until it reaches a smooth consistency. Put it on a lightly floured surface and knead with your hands. Place the dough in a lightly oiled bowl. Wrap or cover with a damp towel and let it rest in a warm place until it doubles in size, about 45 minutes. Roll the dough out into a large circle 1/8-inch thick and about 25 inches in diameter. Place the dough on a pizza stone or baking sheet, sprinkle with the Asiago and Fontina, and top with the cubed potatoes. Drizzle the remaining olive oil on top of the pizza, then sprinkle it with fresh pepper, rosemary, and Parmesan. Cover again, and allow to rise in a warm place for 25 minutes. Place in the oven and bake for about 35 minutes or until golden brown and crispy.