add 1 tablespoon of mature sourdough starter into 100g water and 100g ( 50/50 flour blend made with whole wheat flour and all purpose flour) place in bowl and set aside for over night. That is your Leaven.

when you are ready to make dough mix 375g water in a bowl and add the leaven and stir to disperse. Add the semolina flour and the bread flour using your hands, mix well so that set aside for autolyse for about 23 to 40 minutes.

After 40 minutes add the salt and rest of warm water to dough and mix well set aside for bulk fermentation.

During first two hours of bulk fermentation, stretch and fold the dough every 30 minutes interval. Then another 3 hours every 1 hour interval. once you finish the bulk fermentation

Then place the dough into a plate with black and sesame seeds

and roll well so that seeds get coated very well. Place it in a banetton and set aside for second fermentation for overnight in refrigerator.

Pre-heat oven to 500F and place a dutch oven along with lid.

When you are ready to bake transfer the dough parchment paper and place it in the hot oven.

Return the loaf to bake and reduce the temperature to 475F and bake for 20 minutes with lid closed.

Then carefully remove the lid and bake for another 20-25 minutes until the crust become brown in color.

Transfer the loaf to cooling rack and set aside for few hours before cutting them.