In a stand mixer or large bowl, combine flour, yeast, salt, rosemary, and olive oil. Stir with a large spoon (or the paddle attachment of the mixer) until incorporated.

To achieve the right consistency, start with 3/4 cup of water and stir until incorporated. Mix in water a couple of tablespoons at a time until the texture seems right, shaggy and wet, but still distinctly a dough.

Cover bowl with plastic wrap and allow to rise at room temperature (70-80 F) until doubled, about 10-12 hours.

Preheat the oven to 450 F. Measure out a piece of parchment paper large enough to line the bottom and sides of the Dutch oven; set aside. When the oven is preheated, place the Dutch oven inside (without the lid) to also preheat.

Meanwhile, prep a floured surface. Gently scrape the dough onto it and fold it over on itself a few times, then gently shape into a ball. This very gentle shaping nevertheless adds important structure to the dough. Cover and let rise for at least 1 more hour.

When the dough is ready, take the Dutch oven out. Carefully line it with the parchment paper, drop in the dough ball, and use a sharp knife or razor to slash the top of the ball. Add the lid, and pop the whole thing back in the oven for 30 minutes.

Remove the lid and bake another 15. Bread should sound hollow if you knock on it, and measure at least 190 F inside. Immediately place on a wire rack to cool.

Allow to cool completely before slicing. Eat plain, with butter, or serve as an appetizer with herbed olive oil for dipping.