In a large bowl combine the flour, salt, and yeast. Stir the dry ingredients well until they are evenly combined. Add the water and stir it until a wet, sticky ball of dough forms and no flour remains on the bottom of the bowl. Loosely cover and let sit at room temperature for 14-18 hours to ferment.
After fermentation, the dough should be wet, sticky, very bubbly, and fluffy. Dust the top of the dough and your hands with flour. Carefully scrape the sticky dough from the bowl, adding a small amount of flour if needed to keep your hands from sticking.
Turn the dough out onto a floured work surface and stretch it into a long, 12-16 inch loaf. It's okay if the loaf is lumpy and uneven. The dough will be very soft and sticky, so don't worry too much about the shape.
Prepare a baking sheet by smearing olive oil over the surface and then sprinkling with cornmeal. Carefully pick up the loaf and transfer it to the prepared baking sheet, reshaping it as needed. Let the dough rise for 2 hours.
Preheat the oven to 425 degrees and bake the loaf for 25 minutes, or until it is golden brown. Let the bread cool on a wire rack before slicing.