The evening before you make your bread, stir together the sourdough starter, water and honey together in a large bowl. Add the flour and salt and mix well, using your hands, if needed, to fully incorporate the flour.

Replenish your sourdough starter with fresh flour and water. Cover the bowl with a damp towel and let rise overnight at room temperature, 12-18 hours.

When you are ready to make the focaccia, Pour 2 tablespoons of olive oil onto a rimmed sheet pan. Place the dough on the pan and flip once or twice to coat completely in oil.. Cover and let rest for 1 1/2 to 2 hours.

Preheat oven to 425 degrees. Gently press and stretch the dough into a rustic rectangle or oval shape, about 14 x9 inches. Use your fingertips to dimple the dough, pressing through to the bottom of the pan. Drizzle with additional olive oil, if desired, then sprinkle with rosemary and coarse salt.

Bake for 20-30 minutes, or until golden brown and crisp on the outside. Cool completely before slicing and serving.