In a large bowl, whisk together…
- 4 cups all-purpose flour or bread flour
- 2 teaspoons salt
- 2 teaspoons instant yeast, (sometimes called rapid rise).
Add…
2 cups warm water, made by combining 1/2 cup boiling water with 1 1/2 cups cold water
Using a rubber spatula, mix until the liquid is absorbed and the ingredients form a sticky dough ball.
Using a generous amount of olive oil, rub the surface of the dough.
Cover the bowl with kitchen towel or plastic wrap and place in the refrigerator for least 12 hours, but no longer than 2 days.
Select either a 9×13-inch pan (which will create a thicker focaccia) or a 13×18-inch rimmed sheet pan (creates a thinner focaccia, which is great for sandwiches). Line the pan with parchment paper or grease with butter. Pour 2 tablesppoons olive oil in to the center of the pan.
Using two forks, deflate the dough by releasing it from the sides of the bowl and pulling it toward the center. Rotate the bowl in quarter turns as you deflate, turning the mass into a rough ball.
Roll the dough ball in the oil to coat it all over, forming a rough ball. Let the dough rest for 3-4 hours.
Preheat oven to 425 degrees.
Sprinkle 2 teaspoons rosemary over the dough.
Pour 2 tablespoon olive oil over the dough. Rub your hands lightly in the oil to coat, then, using all of your fingers, press down to create deep dimples. If necessary, gently stretch the dough as you dimple to allow the dough to fill the pan.
Sprinkle with flaky sea salt all over.
Transfer the pan to the oven and bake for 25-30 minutes, until the underside is golden and crisp.
Remove the pan from the oven and transfer the focaccia to a cooling rack. Let cool for 10 minutes before cutting and serving.