Mix Dough Ingredients:

In a large mixing bowl, whisk together the flour, salt, sugar, and instant yeast. Pour in the warm water and 2 tablespoons of the olive oil. Mix using a wooden spoon or your hands until a rough, shaggy dough comes together.

Knead and Rise:

Turn the dough out onto a lightly floured work surface and knead for 5-6 minutes until it becomes smooth and elastic. Lightly coat a clean bowl with olive oil, place the dough inside, cover with a damp kitchen towel or plastic wrap, and allow to rise for 1-1.5 hours until it has doubled in volume.

Stretch and Second Rise:

Brush a 9x13-inch baking pan or sheet generously with oil. Carefully transfer the risen dough into the pan. Using your fingertips, stretch and press the dough evenly to cover the entire pan. Cover once more and let it rise for an additional 30-45 minutes.

Dimple and Season:

Heat the oven to 425°F (220°C). Drizzle the remaining 2 tablespoons of olive oil over the dough. With oiled fingers, create dimples by pressing gently into the dough at random intervals. Sprinkle generously with flaky salt and, if desired, fresh rosemary or other herbs.

Bake Focaccia:

Bake for 20-25 minutes until the focaccia is golden brown and the edges are crisp.

Cool and Serve:

Allow to cool slightly in the pan, then transfer to a wire rack. Cut into pieces and serve warm, or store for later.