In a large bowl, whisk together all purpose flour, bread flour, and salt.
In a medium bowl whisk together water, sourdough starter, and olive oil until starter has dissolved.
Add wet ingredient mixture to dry ingredients mixture. Mix just until a shaggy dough forms. Cover loosely with a towel or plastic wrap and let sit for 20-30 minutes.
With wet hands, stretch and fold the sides of the dough into the middle until the dough becomes a fairly smooth ball. Avoid overworking the dough, stop once all the remaining dry bits are incorporated.
Transfer dough to a clear bowl or container. Mark the position of the top of the dough with a washable marker or rubber band. Cover loosely with plastic wrap or a towel and proof until doubled in volume, about 8-12 hours (see note).
Grease the bottom of a 12-inch cast-iron skillet with about 2 tbsp olive olive. Transfer dough to skillet. With wet hands, press your fingers into the dough repeatedly, starting from the middle and working your way out until the dough reaches the edges of the pan. If dough starts to resist further stretching, stop and allow the dough to rest for 5 minutes before stretching further.
Cover with lightly greased plastic wrap or a towel and allow to rise until puffy and about doubled in volume, around 2-4 hours.
Preheat oven to 400°. Top as desired, pressing toppings into the dough. Brush the top of the dough with about 1 tbsp olive oil, or top with pesto.
Bake for about 35-40 minutes or until golden brown and internal temperature of at least 190°. Remove to a wire rack to cool.