In a large mixing bowl, combine the flour, instant yeast, and salt.
Add the water and stir with a wooden spoon or spatula until a shaggy, sticky dough forms.
Cover the bowl with plastic wrap or a clean kitchen towel and let it rest at room temperature for 12 to 18 hours, until the surface is dotted with bubbles and the dough has doubled in size.
Lightly flour a work surface and place the dough on it. Sprinkle the dough with a little flour and fold it over on itself once or twice. Shape it into a ball.
Place a large piece of parchment paper on a kitchen towel and dust it generously with cornmeal or flour. Place the dough seam side down on the parchment paper. Cover it with another kitchen towel and let it rise for about 2 hours, until it has doubled in size.
About 30 minutes before the dough is ready, place a 5- to 6-quart heavy covered pot (such as a Dutch oven) in the oven and preheat to 450°F (230°C).
Carefully remove the hot pot from the oven. Lift the dough with the parchment paper and place both into the pot. Cover with the lid and bake for 30 minutes.
Remove the lid and bake for an additional 15 to 20 minutes, until the loaf is deep golden brown and crusty.
Remove the bread from the pot and let it cool completely on a wire rack before slicing.