Directions

• Step 1
  To create the sponge, combine 1 cup water and yeast, stir to dissolve, and let stand 5 minutes. Add all-purpose flour and beat for 1 minute. Cover and let stand at room temperature 8 hours.
• Step 2
  Add to the sponge 1 cup water, olive oil, semolina, salt, and enough bread flour to make a soft dough. Turn out onto a floured work surface and knead 8–10 minutes. Add flour only to reduce stickiness. Return to bowl, dust with flour, cover with plastic, and rise at room temperature until doubled in volume, about 1 hour. Punch dough down, fold it in half, and let it rise again, until doubled, about 45 minutes.
• Step 3
  Line a baking sheet with parchment, and sprinkle with cornmeal. Turn risen dough onto a floured surface, and divide into 2 equal portions. Shape into round loaves, place onto prepared pan, cover loosely with plastic wrap, and set aside to proof for 30 minutes. Preheat oven to 375°F.
• Step 4
  Dust the top of the risen loaves generously with flour. Using a serrated knife, cut decorative slash marks into the surface of the dough, about ½" deep. Place a pan of cold water at the bottom of the oven to create steam. Bake until golden brown and hollow sounding, about 30–40 minutes. Cool completely on a rack before serving.