Instructions

Sift whole-wheat flour through fine-mesh strainer into bowl of stand mixer; discard bran remaining in strainer. Add all-purpose flour, salt, and yeast to mixer bowl. Fit stand mixer with dough hook, add water, and knead on low speed until cohesive dough forms and no dry flour remains, 5 to 7 minutes. Transfer dough to lightly oiled large bowl, cover with plastic wrap, and let rest at room temperature for 30 minutes.
Holding edge of dough with your fingertips, fold dough over itself by gently lifting and folding edge of dough toward center. Turn bowl 45 degrees; fold again. Turn bowl and fold dough 6 more times (total of 8 folds). Cover with plastic and let rise for 30 minutes. Repeat folding and rising every 30 minutes, 3 more times. After fourth set of folds, cover bowl tightly with plastic and refrigerate for at least 16 hours or up to 48 hours.
Transfer dough to lightly floured counter, stretch gently into 8-inch round (do not deflate), and divide in half. Working with one piece of dough at a time, gently stretch and fold over 3 sides of dough to create rough triangle with 5-inch sides (photo #1). Transfer to lightly floured rimmed baking sheet, seam side down, and repeat with remaining piece of dough. Cover dough loosely with plastic lightly coated with vegetable oil spray and let rest at room temperature until dough is relaxed and no longer cool to the touch, 30 minutes to 1 hour.
Place baking stone on lower-middle rack of oven and heat oven to 450 degrees. Line two overturned rimmed baking sheets with parchment paper and dust liberally with cornmeal. Transfer one piece of dough to lightly floured counter and, using rolling pin, gently roll into triangular shape with 8-inch base and 10-inch sides, about 1/2 inch thick (photo #2). Transfer dough to parchment with base facing short side of pan (photo #3).
Using pizza cutter, make 6-inch-long cut down center of triangle, through dough to sheet, leaving about 1½ inches at either end. Make three 2- to 3-inch diagonal cuts through dough on each side of center cut, leaving 1-inch border on each end of cuts, to create leaf-vein pattern (cuts should not connect to one another or to edges of dough.)
Gently stretch dough toward sides of pan to widen cuts and emphasize leaf shape; overall size of loaf should measure about 10 by 12 inches. Cover loosely with plastic lightly coated with oil spray and let rest at room temperature until nearly doubled in size, 30 to 45 minutes. Twenty minutes after shaping first loaf, repeat rolling, cutting, and shaping with second piece of dough. (Staggering shaping of loaves will allow them to be baked in succession.)
Brush top and sides of first loaf with 2 tablespoons oil. Sprinkle loaf evenly with ½ cup cheese and 1 teaspoon pepper. Slide loaf from baking sheet, on parchment, to baking stone and bake until golden brown, 18 to 22 minutes, rotating parchment halfway through baking. Transfer to wire rack and let cool for at least 15 minutes before serving. Repeat topping and baking with second loaf.