Servings: Serves 8
Ingredients Nonstick cooking spray3/4 tsp. active dry yeastKosher salt3 1/2 cups durum flour (not semolina flour); available at KingArthurFlour.com2 Tbsp. olive oil1 tsp. chopped rosemary1/4 tsp. red pepper flakes1/2 pound baby arugula1/3 pound Pecorino cheese , preferably studded with black truffle, shaved; available at igourmet.com
Lightly grease a large sheet tray with cooking spray; set aside. Put cup warm water (100° to 110°) into a small bowl. Add yeast; stir and set aside for 2 minutes. Meanwhile, put 1/2 cup warm water (100° to 110°) and 2 teaspoons salt into a large bowl; set aside. Add yeast mixture and flour to bowl with salt water and stir into a rough dough. Turn out onto a floured surface and knead until smooth and soft, about 5 minutes. (Alternately, skip the kneading and mix on medium speed in a stand mixer, fitted with the dough hook attachment, for the same amount of time.)
Shape dough into eight (3 to 3 1/2 ounces) balls and transfer to prepared sheet tray. Spray dough lightly with cooking spray, then cover with plastic wrap and set aside until softened and almost doubled in size, about 3 hours.
Arrange a large pizza stone in the oven, then preheat oven to 500°. Working with one ball of dough at a time, gently roll out into an 8- to 9-inch circle, being careful not to crease or tear holes in the dough. (If creased, torn, or pressed too firmly, dough won't inflate when baked.) Carefully arrange the first dough circle on pizza stone and bake until dough inflates, 1 to 2 minutes. Transfer to a large plate and use scissors to cut around the center of the puffed flatbread, separating the top and bottom layers. Reassemble flatbread by laying the top piece on bottom piece; wrap it in a clean kitchen towel and place a heavy plate on top. Repeat rolling, baking, and cutting process with remaining dough. Put each new flatbread on top of the previous one, replace the towel, and top stack with the heavy plate.
Reduce oven temperature to 250°. Arrange flatbreads in a single layer on two large baking sheets and bake, flipping occasionally, until dried out, about 1 hour.
When ready to serve, heat oven to 500°. Brush flatbreads all over with oil and sprinkle with salt to taste, rosemary, and pepper flakes. Bake, flipping once, until golden brown and crisp, 3 to 5 minutes.
Cut each flatbread in half; top all with arugula and shaved Pecorino. Arrange 2 slices per plate; serve.