In a large bowl, combine the flour and water. Mix until no dry bits remain. Cover with a damp cloth and let it rest for 30 minutes (this is called autolyse—it helps develop gluten).

After the autolyse, add the sourdough starter and salt. Mix well until the dough is cohesive.

Let the dough rest at room temperature for 4-6 hours, depending on the temperature. During this time, perform 3-4 sets of stretch-and-folds (once every 30-45 minutes). This strengthens the dough.

Once the dough has risen and looks puffy, turn it out onto a floured surface. Shape it into a tight ball or batard (oval).

Place the shaped dough into a floured banneton (proofing basket) or a bowl lined with a floured kitchen towel. Cover and refrigerate overnight (8-12 hours) for a slow, cold fermentation.

Preheat your oven to 230°C (450°F) with a Dutch oven inside. Once hot, transfer the dough to the Dutch oven, score the top with a razor blade, and bake covered for 20 minutes.

Remove the lid and bake for another 20-25 minutes until golden brown.

Let the bread cool on a wire rack for at least an hour before slicing. This allows the crumb to set and flavors to deepen.