Sourdough Focaccia

Mixing the dough - Pour the starter into the bottom of your mixing bowl, then add the water - the starter will float. Whisk until the starter is incorporated into the water - it will be milky and frothy on the edges. Measure in the flour, then the salt. Using a fork, mix, scraping the sides of the bowl, until all of the water has been absorbed into the flour and there’s very little flour left in the bowl.
Autolyse - Cover the bowl and let it stand for at least an hour. Bring the dough together into a ball, using stretches and folds, grabbing the dough from the outside, stretching it up and over itself, into the center, turning the bowl as you go, about 15 turns.
Bulk fermentation - Cover and set aside until puffy and alive and not too sticky.
Shaping - Using your dough scraper, dump the dough into a parchment-lined baking dish. Spray with oil and use your hands to push the dough out to fill the dish.
Final proofing - Let the dough rise again. It will be puffy and voluminous, with lovely bubbles popping up.
Topping - Preheat the oven to 400℉. Peel and thinly slice the garlic. Pull the rosemary leaves from the stems and chop finely. Spray the dough with a bit more olive oil, then push your fingertips into the dough to create dimples. Push the slices of garlic into the dough and sprinkle with rosemary.
Baking - Bake for 30 minutes or until golden brown. Shower with flaky sea salt as soon as it comes out of the oven.