1. In a large bowl, whisk together flour, salt, and yeast. If using active dry yeast, proof it first in warm water with a pinch of sugar until foamy (about 15 minutes).
2. Add the lukewarm water and stir with a spatula or fork until a sticky, shaggy dough forms.
3. Drizzle 2 tablespoons olive oil over the dough and rub it lightly over the surface to prevent drying. Cover with a damp towel, plastic wrap, or cloth.
4. For best flavor and texture, refrigerate the dough for a long, slow cold fermentation of 18 to 72 hours. For a quicker method, let the dough rise at room temperature for 1.5 to 2 hours until doubled.
5. Prepare pans by greasing with butter and olive oil.
6. Remove dough from fridge (or after first rise), deflate gently with a fork or by hand, divide if needed, and transfer to prepared pans. Stretch and press dough towards pan edges and let rise again at room temperature for 2 to 4 hours until puffed and nearly doubled.
7. Preheat oven to 425°F (220°C), middle rack.
8. If using, sprinkle rosemary or other herbs evenly over the dough. Drizzle remaining olive oil on top. Use oiled fingertips to create deep dimples across the surface.
9. Sprinkle flaky sea salt generously over the top.
10. Bake for 25 to 30 minutes until golden brown and crisp on the bottom.
11. Remove from oven and transfer to a cooling rack. Let cool 10 minutes before slicing.