In a bowl, combine warm water and yeast. Let it stand for about 5-10 minutes until it becomes frothy.

In a large mixing bowl, whisk together the flour and salt. Make a well in the center and pour in the yeast mixture along with olive oil. Stir until a shaggy dough forms.

Transfer the dough to a lightly floured surface and knead for about 5-7 minutes until smooth and elastic.

Place the dough in a lightly oiled bowl and cover with a kitchen towel. Let it rise in a warm place for 30-45 minutes or until it doubles in size.

After the rise, punch down the dough. Transfer it to a greased baking sheet and stretch it into a rectangle. Use your fingers to create dimples all over the surface.

In a small bowl, combine minced garlic, rosemary (if using), and olive oil. Brush this mixture generously over the focaccia, filling those dimples. Sprinkle with Parmesan cheese and coarse sea salt.

Cover the dough again and let it rise for another 20-30 minutes.

Preheat your oven to 425°F (220°C). Bake the focaccia for 20-25 minutes until golden brown.

Let the focaccia cool slightly before slicing. Serve it warm and enjoy the heavenly aroma!