How to Make It
Set a pizza stone or oven tiles in the bottom third of the oven. Preheat the oven to 400°, allowing at least 45 minutes for the stone to heat. Arrange the potatoes in a single layer on a lightly oiled baking sheet, sprinkle with salt and bake in the upper third of the oven for about 30 minutes, or until tender. Let cool slightly.
In a food processor, combine the parsley, walnuts, garlic and 1/2 teaspoon of salt; pulse until finely chopped. With the machine on, add the oil in a thin stream and process until the pesto is smooth.
Raise the oven temperature to 500°. Roll or stretch 1 piece of the Pizza Dough into an 8-inch round. Place the dough on a floured pizza peel or inverted cookie sheet and arrange one-quarter of the potatoes on top, leaving a 1/2-inch border of dough. Drizzle with one-quarter of the pesto and top with one-quarter of the Fontina and Parmigiano-Reggiano. With a quick motion, slide the pizza onto the hot stone and bake for about 8 minutes, or until the cheese is bubbling and the bottom of the crust is golden and crisp. Transfer the cooked pizza to a plate and serve hot. Repeat with the remaining dough, potatoes , pesto and cheese.