In a large mixing bowl, whisk together the flour, yeast, and the salt. You can also add in spices or herbs of choice here. I like to add about 1 1/2 tbsp of fresh rosemary.
Add the warm water to the bowl. Make sure the water is just warm and not hot. Stir with a spoon or rubber spatula until well combined. It will be a very wet dough, almost like a thick batter.
Cover with plastic wrap or a towel and let sit at room temperature until about double in size. This will take about 45 minutes for rapid rise yeast, and an hour and a half with active dry yeast.
Do not punch down the dough. Add about 1 TBSP of oil to the bottom of a cast iron skillet or any other oven safe skillet (a 10″ or 12″ skillet works well).
Drizzle about a tablespoon of the oil over the dough and also drizzle some on your hands. Rub the oil on your hands, this will help the dough not stick. Gently release the dough from the sides of the bowl and then gather it all up in your hands. Gently shape it into a ball. This will be kind of difficult because the dough is sticky, but just do your best. It doesn’t need to be perfect.
Place the dough in the oiled skillet, cover loosely with a towel. Let it rise again until full of air – about 30 minutes for rapid rise yeast and 1 hour for active dry yeast.
Preheat the oven to 400ºF.
Drizzle a little more oil over the top of the bread, and score the dough with a knife creating an X or a few slices across the top. Sprinkle with coarse salt and rosemary leaves if desired.
Bake for 35-40 minutes until the top is starting to brown. Then turn on the broiler for about 5 minutes and watch the bread closely. This is just to help the top brown up some more.
Allow the bread to cool for at least 1 hour before slicing and preferably longer. Letting the bread cool before slicing will solidify the texture and also help it to stay fresh longer.
Store sliced bread open at room temperature, sliced side down on a cutting board for up to 48 hours. After that, more it to a bag and seal it. I prefer to slice it up and freeze it after 2 days. It refreshes well from frozen in the toaster.