In a large bowl, combine the starter, salt, and water. Stir with a spatula or spoon. Add the flour and mix again until you don’t see any dry spots. The dough will look shaggy and sticky—that’s exactly how it should be.

After 30 minutes, do a round of stretch and folds. Reach under the dough, lift it up, and fold it over itself. Turn the bowl and repeat this 8–10 times. Then cover the bowl again.

Let the dough rise at room temperature (around 21°C or 70°F) for 4 to 18 hours, until it’s almost doubled in size. The rise time will depend on how warm your kitchen is and how active your starter is.

Grease a 30 x 20 cm baking dish with 1–2 tablespoons of olive oil (use 2 tablespoons if you’re using a ceramic or glass dish). Gently transfer the dough into the dish and flip it over so both sides are coated with oil. Cover and let it rise in a warm spot for 1.5 to 3 hours, until the dough looks soft and bubbly.

Preheat your oven to 220°C (425°F). With oiled fingers, press gently into the surface of the dough to create dimples. The dough will spread out a little as you do this. Don’t worry if it doesn’t touch the edges—it will expand while baking.

Add your toppings if you’re using any—cherry tomatoes, rosemary, olives, or garlic all work well. Press them in gently so they stay in place while baking. Drizzle a bit more olive oil over the top and sprinkle with flaky salt.

Bake for 30–35 minutes, until the top is golden and the bottom is crisp. If the top is browning too quickly, loosely cover it with foil for the last 5 minutes. Let it cool in the pan for at least 20 minutes before slicing.