In a large bowl, mix the flour and salt and stir to combine. Add the yeast and water to the flour and stir with a spoon until a sticky dough forms and no pockets of raw flour remain. (If you wanted to add cheese or herbs, do that here and stir them in.)
Cover with plastic wrap and set aside for 18 to 24 hours. Until the dough more than doubles and has lots of tiny bubbles in it.
When you're ready to bake, preheat the oven to 450 and put your 5 quart (or smaller) cast iron pot and the lid to heat up. Heat for 20 to 30 minutes.
When the pot is ready, remove it from the oven and set aside. Sprinkle the dough with a tablespoon of flour or so and flour your hands well. Make a fist and punch right into the middle of the dough to flatten it. Then working gently, shape the dough into a ball. Flour your hands as needed, but avoid adding any more flour to the dough. It will still be sticky. That's okay.
Sprinkle another tablespoon of flour inside the bottom of your pot and then set the dough inside. Cover with the lid and bake 30 minutes, then remove the lid and bake an additional ten. Transfer to a wire rack to cool.