7 1/4 cups all-purpose flour
1 tablespoon kosher salt
Olive oil, for greasing and brushing
Cornmeal, for sprinkling
Crushed ice
1 1/2 cups finely grated Pecorino Romano cheese (4 ounces)
Extra-virgin olive oil, for drizzling
Freshly ground black pepper
In a medium saucepan, heat 3 cups of water to 80°. Transfer 2 tablespoons of the warm water to a small bowl and whisk in the yeast. In a large bowl, combine the flour with the remaining warm water and stir with a wooden spoon until a shaggy dough forms. Cover both bowls with plastic wrap and let stand for 30 minutes. Mix the salt into the yeast and add to the dough in the large bowl. Knead until all of the liquid is absorbed; the dough will be quite wet. Cover with plastic wrap and let stand at room temperature for 30 minutes. With a dampened hand, lift one edge of the dough, stretch it up and fold it over the top of the dough. Turn the bowl a quarter turn, lift up the edge of the dough, stretch it up and fold it over the top. Repeat until you've turned the bowl all the way around. Cover the bowl with plastic wrap and let the dough stand for 30 minutes. Repeat the lifting and folding one more time, then transfer the dough to a large oiled bowl. Cover with plastic wrap and let stand at room temperature until tripled in bulk, about 12 hours. Turn the dough out onto a lightly floured work surface and cut into 6 equal pieces. Take 1 piece of dough and pull the edge into the center, then place seam side down on the work surface. Roll the dough into a ball and set on an oiled baking sheet. Repeat with the remaining 5 pieces of dough, arranging them 3 inches apart on the sheet. Brush the rounds with canola oil and cover with plastic wrap. Refrigerate for at least 8 or up to 12 hours. Let the dough stand at room temperature for 30 minutes. Preheat the broiler. Place an inverted baking sheet or a pizza stone in the oven 8 inches from the heat. Invert a second baking sheet and dust liberally with cornmeal. On a lightly floured surface, use your fingertips to press 1 ball of dough into a 6-inch round, leaving a border around the edge and keeping the center slightly thicker than the rest. Use your palms to press the dough into a 10- to 12-inch round. Transfer to the cornmeal-dusted sheet and slide onto the hot sheet in the oven. Place 2 tablespoons of ice in the center of the dough and bake for about 8 minutes, until golden. Immediately sprinkle 1/4 cup of the cheese all over the pizza, drizzle with olive oil and season with pepper. Serve immediately. Repeat to make 5 more pizzas.