In a large bowl add starter and water and mix well. Then add bread flour and semolina flour combine everything and set aside for 30 minutes

Then add salt and mix again and set aside for another 6-8 hours. If you want, you can strengthen the dough with folding at every 30 minutes for next 2 hours and then 1-hour interval for 2 hours and finally set aside for 2-3 hours.

When you are ready to shape make the boule and brush with water and then coat with black and white sesame seeds and transfer to banneton or mold.

Refrigerate for overnight, next morning pre-heat oven to 450Score the dough and Transfer the dough to cold Dutch oven and bake for 10 minutes at 450F and then reduce the temperature to 425 F and bake 25 minutes with lid on. Then remove the lid and bake for another 10 minutes or until loaf develop golden color and when you tap the loaf it makes whole sound or register 210 F internal temperature.

Cool the loaf and cut it into slice and enjoy.