In a large bowl, whisk flour, salt, and instant yeast.
Stir in warm water and olive oil until a shaggy dough forms—no dry pockets. It should look sticky.
Fold in garlic, rosemary, and pepper if using. Scrape down the bowl.
Cover the bowl tightly with plastic wrap or a lid.
Let it rise at room temperature for 8–12 hours until doubled, puffy, and bubbly on top.
Dust a work surface with flour. Turn the dough out gently with a spatula.
With floured hands, do 4 envelope folds: pull one side up and over to the center, rotate 90 degrees, repeat three more times.
Flip seam-side down and cup your hands to tighten into a round. Avoid deflating the bubbles.
Place on a parchment square. Dust lightly with flour. Cover with a towel and rest 30–45 minutes while the oven heats.
Place a 4–6 qt Dutch oven with lid on the middle rack.
Preheat to 450°F (232°C) for at least 30 minutes.
Score the top with a sharp knife or lame (one deep slash or a few shallow ones).
Carefully remove the pot, lift the dough by the parchment, and lower it into the pot.
Sprinkle with a pinch of coarse salt. Cover and bake 30 minutes.
Remove the lid and bake another 12–18 minutes until deep golden and crusty.
Lift bread out by the parchment. Cool on a rack at least 45–60 minutes before slicing.
