Mix together durum wheat flour, dry yeast and water and leave to ferment covered at room temperature for 12-24 hours.
For the dough:
Mix the durum wheat flour, durum wheat semolina, dry yeast, salt, olive oil, water and the pre-dough until a soft, sticky dough is formed.
Place the dough on a floured work surface and knead for 10 minutes until it is smooth and elastic.
Place the dough in a bowl lightly coated with oil and let rise for about 1 1/2 hours until it has doubled in volume, then knock it off and let it rest for 10 minutes.
Divide the dough into 2 portions and form 2 round loaves, roll in semolina and place on a baking sheet. Flatten the loaves with your hands and let rise, covered, for about 1-1 1/2 hours until they have doubled in volume.
Preheat the oven to 240 ° C, put the bread in the oven and reduce the temperature to 200 ° C. Bake the breads for 30 minutes, until the crust is golden brown and they sound hollow.