Mix the flour, salt and yeast in a large bowl with a fork. Add olive oil, if using, and 2 cups of water (at about 70ºF—see Kitchen Notes). Stir with a wooden spoon until everything is mixed together—the dough should be sticky and shaggy. If it seems dry, add a tiny bit more water. Conversely, if it's not quite shaggy, add a little more flour.
Cover it with plastic wrap, or waxed paper, and let it sit for about 18 hours. Just let it sit there. It may take an hour or two less if your kitchen is on the warm side, and a bit longer if your kitchen runs cold. The dough is ready for the next phase when the top is dotted with bubbles.
Lightly flour a work surface. Pour the dough onto it (you may have to gently scrape it out of the bowl) and just fold it over a couple of times. Just pick up one side and fold it across and then do the same to the perpendicular side. The dough should be quite soft but not particularly sticky. If it is sticky, sprinkle it with flour and work it into the dough—the goal is that it doesn't stick to your hands or the surface. Put the plastic wrap on top of it and let it sit for 15 or 20 minutes.
Shape the dough into a ball. You will probably need to add just a little flour to keep the dough from sticking. Generously coat the tea towel with cornmeal (or just use a silicon baking mater). Set the dough on it, seam side down, and dust with more cornmeal.
Cover lightly with plastic wrap, waxed paper or another tea towel, and let sit for 2 more hours, until it has about doubled in size. You will know it is ready when you poke the top and the indentation doesn’t quickly fill in.
Two things at once warning: about 90 minutes into this process, turn on your oven to 450ºF and put the Dutch oven, including the cover, in it to heat up.
When the dough is ready, take out the Dutch oven, set it someplace heatproof—just the stovetop is fine, and remove the lid. Pick up the dough and roll it into the pot, seam side up. Don’t worry if it lands weird or looks catawampus. It will straighten out. (See Kitchen notes.) Straightaway, put the lid on the pot and put it in the oven.
Bake the bread for 30 minutes, then take off the lid and bake about another 18 to 25 minutes until it is beautifully golden brown. Take the pot out of the stove, and promptly remove the bread to a cooling rack. Bittman recommends using tongs or a spatula, but I just rolled it onto its side and grabbed it fast with my stubborn hand.
Let it cool. Done.