Combine 200g flour, 4g yeast, and 150ml water in a bowl.
Beat the mixture into a thick batter.
Oil a work surface and knead the dough for five minutes.
Cover with a damp towel and rise for six hours at room temperature.
Add remaining flour, oil, yeast, and 75ml water into a food mixer.
Mix ingredients using a dough hook attachment.
Dissolve salt in remaining 75ml water and gradually mix for 10 minutes.
Transfer dough to an oiled square container and close the lid.
Rest until dough rises three-quarters of the way up the container.
Tip dough onto a surface floured with equal parts flour and semolina.
Split dough in two, stretch into shape, and place on a tray.
Preheat oven to 220°C.
Prove for 30 minutes and bake for 30 minutes.