Step 1

In a large bowl, stir together the semolina flour, 00 flour, all-purpose flour, salt, and yeast. Add the lukewarm water and stir until the ingredients form into a slightly dry, shaggy dough, about 1 minute. Cover the bowl with plastic wrap to keep in the moisture and let the dough rise at room temperature (between 65º and 75ºF or 18° to 24°C) for at least 12 hours and up to 18 hours. After this time, the surface of the dough should be covered with small bubbles and the dough should have risen significantly.

Step 2

If you’re making a round or rectangular loaf, gently run a spoon around the bowl to deflate the dough. Use the spoon to gently fold the dough over itself. Let the dough rest for 15 minutes. If you’re making a braided loaf, flour a board or surface with 1/4 cup all-purpose flour and turn the dough out onto it. Deflate the dough by pressing and kneading the flour into the dough until the dough no longer feels quite as sticky. Roll the dough into a long loaf. Cut the loaf into 3 equal pieces and, using your hands, roll each piece evenly into a rope about 12 inches long. Place the ropes on a parchment-lined baking sheet. Braid the bread starting in the middle of the ropes. Take the left rope and cross it over the middle piece. Take the right rope and cross it over the rope that is now in the middle. Repeat crossing left over center, followed by right over center until you reach the end, as if you’re braiding hair. Pinch the bottom ends together and tuck them under the loaf. Repeat for the other side. Cover and let rise until doubled in size.

Step 3

If you’re making a round or rectangular loaf, spread about 1/4 cup semolina flour onto a cotton dish towel. Take the dough out of the bowl and use your hands to shape the dough into a rectangle or ball, depending on the shape of your pot or Dutch oven. The dough will be sticky and shaggy. Fold the dough into thirds and place the dough seam-side down on the dishtowel. Sprinkle some more semolina on the bread. Bring the sides of the towel over the bread to cover loosely. Let the dough rise until double its original size, about 2 hours. If you’re making a braided loaf, move on to step 4.

Step 4

While the dough is rising, place an oven rack in the middle position and preheat the oven to 450ºF (230°C).

Step 5

About 30 minutes before the dough is finished rising, place a heavy clay-covered, ceramic, or cast iron pot or Dutch oven with a minimum size of 3 quarts into the oven and heat the pot while the dough finishes rising.

Step 6

If desired, after the dough has risen, lightly brush it with melted butter or lightly beaten egg white and sprinkle with sesame seeds. Remove the pot from the oven, gently lift the dough from the towel, and place it into the pot seam side up. Cover the pot and bake for 30 minutes. Uncover and bake until the bread is brown on the outside, about 10 minutes longer. Remove the loaf from the pot and cool on a wire rack for an hour before slicing.