In a large mixing bowl, whisk together the flour, salt, and instant yeast until combined.
Add the warm water, minced garlic, and 1 tablespoon of the chopped rosemary to the dry ingredients.
Stir with a wooden spoon or spatula until a shaggy, sticky dough forms and no dry flour remains.
Cover the bowl with plastic wrap or a damp cloth and let the dough rise in a warm, draft-free area for 1.5 to 2 hours, or until doubled in size.
Place a 10-inch cast-iron skillet into the oven and preheat to 425°F (220°C).
Carefully remove the hot skillet from the oven and coat the bottom with 1 tablespoon of olive oil.
Gently transfer the risen dough into the center of the hot skillet, being careful not to deflate it entirely.
Drizzle the remaining 1 tablespoon of olive oil over the top and sprinkle with the remaining rosemary and an optional pinch of sea salt.
Bake for 25 to 30 minutes until the crust is deep golden brown and the internal temperature reaches 190°F (88°C).
Remove the bread from the skillet immediately and transfer to a wire rack to cool for at least 15 minutes before slicing.