Mix flour, salt and yeast in a large bowl. Pour in water and olive oil. Mix with a spoon until no dry flour remains.

Cover, rest 15 min. Wet your hand, do one round of stretch and folds. Repeat twice more at 15-min intervals.

Cover and let rise at room temp 1.5 hours until puffy and doubled. (Alternatively: refrigerate overnight then return to room temp for 1 hour before shaping.)

Generously oil a 23x33cm baking tray. Tip dough into the tray, turn to coat both sides in oil. Gently stretch to fill tray. Cover, rest 45 min.

Preheat oven to 220°C fan-forced.

Drizzle 2 tbsp olive oil on top. Using oiled fingertips, press down firmly through to the tin to create dimples all over.

Scatter rosemary leaves and flaky salt across the top.

Bake 20-25 minutes until deep golden. Cool in tin 10 min. Drizzle with extra olive oil. Cut into squares and serve warm.