Start by feeding your sourdough starter in the morning so that you have 180g ready for this recipe, plus some extra to keep it going.

When the starter has doubled in size, usually within 4-5 hours depending on the ambient temperature, combine the flour and water. Add 600g of flour to the bowl of a stand mixer fitted with the bread hook attachment. While the machine is running on low speed, gradually drizzle in 450g of warm water. Mix for just 1-2 minutes until the dough comes together, though it should still look a bit rough.

Cover the bowl with a clean towel and let the dough rest for 30 minutes.

After this initial rest, add the sourdough starter to the dough. Mix on low speed to combine, then slowly add the 13g of fine sea salt. Continue mixing on low for another 2-3 minutes until the starter is fully incorporated into the dough, which will be quite sticky at this stage.

You can leave the dough in the stand mixer bowl or transfer it to a clean bowl. Perform a series of envelope folds every 20 minutes: take one side of the dough with both hands, stretch it up and fold it over to the other side, rotate the bowl 25 degrees, and repeat this process four times. Cover and let the dough rest between each set of folds. Do this folding routine three times in total, resulting in 12 folds.

Cover the dough and let it rise until it has doubled in size and passes the windowpane test. At this point, cover the bowl tightly with plastic wrap and refrigerate overnight.

In the morning, remove the dough from the fridge. Grease your baking pan with 1-2 tablespoons of olive oil. Gently turn the dough out into the pan and, using both hands, stretch it in an up-and-down motion a few times. Don’t worry if it doesn’t fully reach the edges of the pan yet.

Allow the dough to rest at room temperature for 3-4 hours.

Once the dough has doubled in size again and has a slightly jiggly consistency, preheat your oven to 425℉.

When the oven is ready, drizzle a generous amount of olive oil over the top of the focaccia. With oiled hands, create dimples in the dough by pressing down with your fingers. Sprinkle fresh rosemary, whole garlic cloves (still in their skins), and optionally, a generous pinch of coarse sea salt over the top.

Bake the focaccia for 23-30 minutes, adjusting the time based on your pan size (closer to 30 minutes for a 9×13 pan versus slightly less for a 10×14 pan) until it achieves a golden brown crust.

Allow the focaccia to cool for 30 minutes before slicing and serving.