1. Prepare the Dough:

• In a large bowl, combine 3 1/4 cups flour, 2 teaspoons salt, 1/2 teaspoon instant yeast, 1 cup warm water, 1/2 cup orange juice, and 1 tablespoon finely grated orange zest.
• Mix the ingredients with a wooden spoon until the flour is fully incorporated, and the dough comes together. The mixture will be sticky, but this is normal.
• Cover the bowl tightly with plastic wrap and let the dough rise in a warm spot for at least 8 hours and up to 24 hours. The dough should more than double in size during this time.

2. Shape the Dough:

• After the dough has risen, sprinkle a little flour on top and gently transfer it to a lightly floured work surface.
• Shape the dough into a ball. Be gentle as you do this, as you don’t want to knock out all the air that developed during the rise.

3. Prepare the Skillet:

• Pour 2 tablespoons of extra-virgin olive oil into the bottom of a 12-inch cast iron skillet, ensuring the entire surface is coated with oil.
• Transfer the dough ball into the skillet, turning it over in the oil to coat both sides. Using the palm of your hand, gently press and stretch the dough to fit the skillet, spreading it towards the edges.
• Cover loosely with plastic wrap, and allow the dough to rise again in a warm spot for 2 hours, until it fills the skillet up to the edge.

4. Final Touches Before Baking:

• After the second rise, preheat your oven to 500°F (260°C).
• Use your fingertips to pop any large bubbles and create deep indentations all over the surface of the dough.
• Drizzle the remaining 2 tablespoons of extra-virgin olive oil over the top of the dough.
• Sprinkle coarse sea salt generously over the surface and poke the fresh rosemary leaves into the dough, distributing them evenly.

5. Bake the Focaccia:

• Transfer the cast iron skillet to the preheated oven. Bake for 20-25 minutes, or until the top of the focaccia is golden brown and crisp.
• Once baked, remove from the oven and let cool slightly before slicing and serving.