01 - Preheat oven to 400°F (200°C). Slice off the top 1/4 inch of the garlic head, drizzle with 1 tbsp olive oil, wrap tightly in aluminum foil, and roast for 30-35 minutes, or until softened. Allow to cool slightly, then squeeze out the roasted cloves and mash them into a paste.
02 - In a large mixing bowl, combine the bread flour, kosher salt, and instant yeast. Add the finely chopped rosemary and the mashed roasted garlic. Pour in the lukewarm water and stir with a spoon until a shaggy, cohesive dough forms.
03 - Cover the bowl securely with plastic wrap or a damp kitchen towel. Let the dough rise at room temperature for 12 to 18 hours, or until it has visibly doubled in size and appears bubbly.
04 - Lightly flour a clean work surface. Gently turn the dough out onto the floured surface. With floured hands, shape the dough into a round ball. Transfer the dough onto a large sheet of parchment paper. Cover with a towel and let rise for an additional 30 to 45 minutes.
05 - Place a Dutch oven with its lid into the oven. Preheat the oven along with the Dutch oven to 450°F (230°C) for a minimum of 30 minutes.
06 - Carefully remove the preheated Dutch oven from the oven. Using the parchment paper as handles, gently lift the dough and place it into the hot Dutch oven. Cover with the lid and bake for 30 minutes. Remove the lid and continue baking for an additional 12 to 15 minutes, or until the crust is deep golden brown and firm.
07 - Transfer the baked loaf to a wire rack and allow it to cool completely for at least 30 minutes before slicing. This step is crucial for the final texture.