THE TOPPING: While the dough is resting for the final 30 minutes, preheat the oven to 450°F. On a baking sheet, toss the diced potato with the oil, rosemary, and salt. Roast for 8 minutes; turn the diced potatoes with a spatula and roast 5 minutes longer, until soft and browned. Meanwhile, heat a skillet over medium heat; crumble the sausages into the skillet and cook for 10 minutes, turning to brown evenly.

TO ASSEMBLE: Working with one piece of dough at a time, lay the dough out on an oiled heavy baking sheet; press and stretch each into an 8-inch round. Top each with one-eighth of the scamorza and one-quarter of the potatoes, then crumble the sausage evenly over each. Season liberally with pepper. Arrange the remaining cheese on top. Bake for 10 to 15 minutes, until the crust is browned and the cheese is melted and slightly browned. Garnish with rosemary sprig and serve