GRILLED PIZZAS WITH POTATOES AND ROSEMARY

Steps:

• Make dough:
• Stir together water, yeast, and sugar in a large bowl and let stand until foamy, about 10 minutes. (If mixture doesn't foam, discard and start over.) Stir in oil, flour, cornmeal, and table salt, then stir until a dough forms.
• Knead on a floured surface, dusting with more flour as needed to prevent dough from sticking, until smooth and elastic, 5 to 10 minutes (dough will be moist).
• Put dough in an oiled deep bowl and turn to coat with oil. Let dough rise, covered with plastic wrap, in a warm place until doubled in bulk, about 1 hour.
• Form dough into pizzas:
• Punch down dough and divide into 6 balls. Roll out 1 ball of dough 1/8 inch thick (about 7 inches in diameter) on a lightly floured surface. Brush off excess flour, then transfer dough to a lightly oiled baking sheet and cover surface of dough completely with plastic wrap. Roll out remaining balls of dough in same manner, covering with plastic wrap and stacking rounds. Wrap baking sheet with more plastic wrap. Chill dough until firm, about 2 to 4 hours or overnight.
• Make potato topping while dough is chilling:
• Preheat oven to 425°F.
• Thinly slice potatoes (1/8 inch thick) using a mandoline or other manual slicer, then toss with oil, garlic, salt, rosemary, and pepper in a large bowl until lightly coated.
• Spread potatoes in 1 layer on 2 lightly oiled baking sheets. Bake in upper and lower thirds of oven, switching position of sheets halfway through baking, until tender, about 15 minutes total. Cool potatoes on sheets on racks.
• Grill pizzas:
• Prepare grill for cooking.
• Remove plastic from 3 dough rounds (if grill is not large, work with 1 piece at a time) and lightly brush dough with some oil. When the fire is medium-hot (you can hold your hand 5 inches above rack 3 to 4 seconds), carefully transfer dough, trying not to stretch it, oiled side down, with your hands to grill rack.
• Grill oiled rounds until undersides are browned, 3 to 4 minutes. Flip over with tongs, then, working quickly, sprinkle each crust with 1/3 cup mozzarella and cover with potato slices, overlapping them and leaving a 1/4-inch border around edge.
• Grill, covered, until undersides are golden and cheese is melted, about 4 minutes.