In a large mixing bowl, combine flour, salt and yeast. Add warm water and stir with a wooden spoon until combined. The dough will be sticky.
Cover the bowl with plastic wrap and allow to rise on your counter, at room temperature, for 12 - 18 hours.
Heat oven to 450 degrees F.
Pour dough out onto floured counter, shape into a ball and place on a piece of parchment paper. Cover the dough lightly with plastic wrap.
Place a cast iron pot, with the lid ON, into the preheated oven for 30 minutes.
Once the pot is hot, remove it from the oven. Remove the plastic wrap off of the dough ball and carefully lift the parchment paper with the dough ball on it, into the pot. Cover with lid and return pot to oven to bake for 30 minutes.
After 30 minutes, remove lid from pot and continue baking, uncovered for 12-15 minutes. Remove from oven and allow bread to cool on a wire cooling rack.
Store bread in an open paper bag, to ensure the crust stays crispy.