01 - Preheat oven to 400°F. Slice off the top of the garlic head, drizzle with 1 tbsp olive oil, wrap in foil, and roast for 30–35 minutes until soft. Cool, then squeeze cloves from skins and mash.
02 - In a large bowl, mix bread flour, yeast, and salt. Add lukewarm water and stir until combined into a shaggy dough. Fold in mashed roasted garlic and chopped rosemary.
03 - Cover with plastic wrap or a clean towel. Let rise in a warm place for 1–2 hours until doubled in size and bubbly.
04 - Turn dough onto a floured surface. Shape into a ball by folding edges inward. Place seam-side down on parchment paper; brush with olive oil and sprinkle with flaky sea salt and extra rosemary if desired.
05 - Cover and rest for 30 minutes while preheating the Dutch oven.
06 - Place empty Dutch oven with lid into the oven and heat to 450°F for at least 30 minutes.
07 - Carefully transfer the parchment with dough into the hot Dutch oven. Cover and bake 30 minutes. Remove lid and bake an additional 12–15 minutes for a golden-brown crust.
08 - Lift bread out and cool on a wire rack at least 30 minutes before slicing.