To make the starter place the ½ cup of water, 1 cup flour and ⅛ teaspoon yeast in a small mixing bowl. Stir to combine. Cover with plastic wrap and let it rest at room temperature overnight for if making the starter in the morning, allow it to rest for about 10 hours before making the dough (which also rests overnight).
Combine the dough ingredients in a large mixing bowl of a stand mixer. Using a spatula, combine the ingredients until they just come together. Attach the dough hook to the mixer and mix until the dough is somewhat smooth but slightly rough. Cover the dough with a lightly greased piece of plastic wrap and allow it to rise in a warm spot for about 3 hours. After 1 hour gently deflate the dough and turn it over. Cover again and continuing to let is rise for 2 more house.
Line a large baking sheet parchment paper and set aside.
Remove the dough from the bowl and place on a lightly floured work surface. Form the dough into one 14-inch round or cut it into 3 or 4 equal pieces. Form each into 6-inch rounds and place them on the parchment line baking sheet.
Lightly spray a piece of plastic wrap with cooking spray and completely cover the loaf/loaves. Place the pan in the refrigerator and allow them to rest overnight.
We ready to bake, remove the loaves from the refrigerator and let them come to room temperature about about 30 minutes.
Preheat oven to 425°F.
Mix ½ cup of water with the egg white and brush it on the loaves. Sprinkle generously with sesame seeds and gently press to adhere.
Bake for 25-30 minute or until golden brown. Remove to a wire rack and cool.