Whisk flour, yeast, and salt in a 3-4 quart bowl with a tight-fitting lid. I like to use my trusty Tupperware. If you don't have a bowl w/lid use plastic wrap on a bowl.
Add the water and stir with a wooden spoon until the dough is mixed well.
The dough will be quite sticky and shaggy looking, but that's OK.
Cover the bowl and set aside for 12-18 hours (up to 24 overnight is fine).
Preheat oven to 450º. Place a cast-iron Dutch oven with the lid into the oven while preheating and heat the pot/lid for 30 minutes.
Meanwhile, scrape the risen dough from the bowl onto a heavily floured surface. (Dough will still be very sticky.)
With floured hands, gently shape the dough into a round loaf, making sure there's enough flour on the surface so the dough doesn't stick. Let the dough just sit there until your pot is preheated.
Take the hot pot from the oven and gently place the dough into the pot.
Cover with the lid and return to the oven and bake for 30 minutes.
Remove the lid at that time and return the pot to the oven for another 10-15 minutes.
Gently shake the loaf onto a cooling rack and enjoy the beautiful aroma. Give it a chance to cool before cutting into the loaf.