Step 1Three to four hours before you wish to make the pizza, prepare the dough. In the bowl of a stand mixer, or a large bread bowl, dissolve the yeast in the water. Add the sugar and stir together. Let sit a minute or two, until the water is cloudy. Stir in the olive oil.
Step 2If you’re using a stand mixer, combine the flour and salt and add to the yeast mixture all at once. Mix together the dough using the paddle attachment, then switch to the dough hook. Knead at low speed at first for about two minutes, then increase the speed and continue to knead until the dough comes away cleanly from the sides of the bowl, about 5 minutes. (Hold the machine down if it starts bouncing around.) Turn out onto a flour-dusted work surface and knead by hand until the dough is smooth and firm, about 1 minute. (If making the dough by hand, combine the flour and salt, then stir the flour into the yeast mixture, 1 cup at a time. As soon as you can scrape the dough into one piece, turn it out onto a lightly floured work surface and knead until the dough is smooth, 8 to 10 minutes.)
Step 3Transfer the dough to a clean, lightly oiled bowl. Cover bowl tightly with plastic wrap, and leave it in a warm spot to rise until just about doubled in bulk, 2 to 3 hours. When it is ready, the dough will stretch as it is gently pulled.
Step 1Heat the oven to 425 degrees and insert a pizza stone to heat. Line a baking sheet with parchment.
Step 2Place the sliced potatoes in a bowl and add 2 tablespoons olive oil, tossing the potatoes until they are evenly coated. Add ½ teaspoon salt and several grinds of pepper, or to taste. Spread the potatoes in a single layer on the baking sheet.
Step 3Roast the potatoes until tender, about 15 minutes. Remove and increase the oven temperature to 450 degrees.
Step 4Remove the dough from the oiled bowl and shape it into a ball: Gently pull down the sides of the dough and tuck them under the dough, working around the dough 4 to 5 times to form a ball. On a smooth, unfloured surface, roll the ball under your palm until it is smooth and firm. Place the ball onto a lightly oiled baking sheet, cover with plastic wrap, and set aside for 15 to 20 minutes to give the ball a chance to relax.
Step 5Oil a 14-inch pizza pan or similarly sized baking sheet. Add the dough and slowly press it out to a circle that is 12 to 14 inches in diameter. (As you work the dough, it will get tight and start to spring back. When this happens, set it aside to rest for a few minutes, then continue until it is fully stretched out.) Using your fingers, form a slightly thicker raised rim around the edge of the circle. Brush everything but the rim with a little olive oil.
Step 6Spread the marinara sauce evenly over the top of the dough, using a small offset spatula or a rubber spatula. Arrange the potato slices on top, overlapping slightly. Sprinkle with rosemary and drizzle over 1 tablespoon olive oil.
Step 7Place the pizza pan on the stone in the hot oven. Bake 12 minutes. Sprinkle over the cheese and return to the oven until the cheese has melted and begun to color slightly, 5 to 8 minutes. Remove from the oven and serve. The pizza can also be served warm or at room temperature.