Add 500 grams (17 1/2 ounces, about 3 1/4 cups) bread flour to a large bowl.

Add 15 grams (0.5 ounces, about 1 tablespoon) Kosher salt to the bowl with the flour.

Add 4 grams (0.15 ounces, about 1 teaspoon) instant yeast to the bowl with the flour.

Add 325 grams (11 1/2 ounces, about 1 1/2 cups minus 1 tablespoon) water to the bowl with the flour.

Mix with hands or a wooden spoon until no dry flour remains.

Cover bowl tightly with plastic wrap, making sure that edges are well-sealed

Let the dough rest on the countertop for at least 8 hours and up to 24 hours. Dough should rise dramatically and fill bowl.

Add 2 tablespoons of olive oil in the bottom of a 12-inch cast iron skillet and swirl to cover sides.

Lightly-flour a work surface.

Sprinkle the top of the dough lightly with flour.

Transfer the dough to the floured work surface.

Form the dough into a ball by holding it with well-floured hands and tucking the dough underneath itself, rotating it until it forms a tight ball.

Pinch the hole in the bottom of the ball to close it.

Holding the dough ball from the bottom, rub the top of the ball in the oil in the pan.

Place the dough in the pan seam-side-down.

Using a flat palm, press the dough around the skillet, flattening it slightly and spreading oil around the entire bottom and edges of the pan.

Cover tightly with plastic wrap and let the dough stand at room temperature for 2 hours.

Adjust an oven rack to the middle position and preheat oven to 550°F.

Set aside 2 tablespoons extra-virgin olive oil

Slice 4 ounces pitted olives

Roughly chop 2 tablespoons fresh rosemary leaves

Set aside coarse salt

At the end of the 2 hours, dough should mostly fill the skillet up to the edge.

Use your fingertips to press the dough around until it fills every corner, popping any large bubbles that appear.

Lift up one edge of the dough to let any air bubbles underneath escape.

Repeat pressing the dough, moving around the dough until there are no air bubbles left underneath and the dough is evenly spread around the skillet.

Spread olives all over the surface of the dough and press down on them with your fingertips to embed slightly.

Drizzle 2 tablespoons olive oil.

Sprinkle with rosemary.

Sprinkle with coarse salt.

Transfer the skillet to the oven and bake until top is golden brown and bubbly and bottom is golden brown and crisp when you lift it with a thin spatula, 16 to 24 minutes.

Using a thin spatula, loosen the focaccia and lift to see the bottom. If it is not as crisp as desired, place the skillet on a burner and cook over medium heat, moving the pan around to cook evenly until it is crisp, 1 to 3 minutes.

Transfer the focaccia to a cutting board and allow it to cool slightly

Slice and serve.