Rosemary Tomato Focaccia

4 cups (512 g) all-purpose flour

2 teaspoons (10 g) kosher salt

2 teaspoons (8 g) instant or active dry yeast

2 cups (455 g) lukewarm water

4 tablespoons olive oil, divided

flaky sea salt

2 teaspoons whole rosemary leaves

1–2 medium tomatoes, sliced, or 1 pint cherry tomatoes, halved

In a large bowl, whisk together the flour, salt, and yeast. Add the water and mix until the liquid is absorbed and the ingredients form a sticky dough ball. Rub the surface of the dough lightly with olive oil. Cover the bowl with a damp tea towel, cloth bowl cover, or plastic wrap and place in the refrigerator immediately for at least 12 hours or for as long as three days.

Grease a 9×13-inch pan with butter. Pour two tablespoons of oil into the center of the pan. Remove the dough from the refrigerator and transfer to the greased baking dish, rolling it in the oil to coat. Let rest for 3 to 4 hours, until a finger pressed into the dough doesn’t spring back.

Preheat the oven to 425°F. Sprinkle the rosemary over the dough and add the remaining two tablespoons of olive oil. Dimple the dough with your fingers and gently stretch it until it fills the pan. Add the tomato slices and sprinkle with flaky sea salt all over.

Transfer the pan to the oven and bake for 25 to 30 minutes, until the underside is golden and crisp. Remove from the oven and transfer to a cooling rack. Let cool for 10 minutes before cutting and serving.