Italian Focaccia (No Knead)

In a large bowl, whisk together the flour, yeast, and salt. Add the warm water and olive oil, and stir until a dough forms. Cover the bowl with plastic wrap and let the dough rise in a warm place for 1 hour, or until doubled in size. Preheat oven to 450 degrees F (230 degrees C). Grease a 9x13 inch baking dish with olive oil. Punch down the dough and place it in the prepared baking dish. Use your fingers to stretch and dimple the dough all over. Drizzle with olive oil and sprinkle with rosemary and flaky sea salt. Bake for 20-25 minutes, or until the focaccia is golden brown and cooked through. Let the focaccia cool slightly before slicing and serving.