Mix flour, water and starter. Rest 30 min. (Mix the dough: Combine 500 grams bread flour, 375 milliliters water, and 100 grams sourdough starter in a large bowl. Mix until no dry flour remains — it will be a shaggy, sticky dough.)
Add salt (Sprinkle 10 grams salt over the dough and squeeze it through your fingers until fully incorporated. The dough will feel slippery at first — keep going until it comes together.)
Bulk ferment 5–8 hrs (or fridge overnight) until puffy. (Cover and leave at room temperature for 5–360 minutes until the dough is noticeably puffy and airy. Alternatively, place it in the fridge overnight for a slower, more flavourful ferment.
Oil pan, stretch dough in, dimple deeply & drizzle oil. (Pour 4 tablespoons olive oil (for pan & drizzle) into a rimmed baking tray and coat generously. Transfer the dough in and gently stretch it toward the edges — don't force it. If it springs back, let it relax for 10 minutes and try again.)
Dimple & drizzle: Using all your fingers, press deep dimples all over the surface of the dough — don't be shy, go right to the bottom. Drizzle more olive oil over the top so the dimples pool with oil.
Proof 1–2 hrs. ( Leave the dough uncovered at room temperature until it looks puffy, bubbly, and has risen noticeably in the pan)
Bake 220°C/425°F for 22–25 min until golden.