Combine water and yeast. Set aside to bubble up and foam. Place flour in a pot large enough to hold dough that will double in size. When yeast has foamed, gently add 1/2 cup of olive oil. Pour over flour, mix and knead until dough forms. Cover and set aside. When double in size (about 2 1/2 hours), knead dough down. Let rise a second time. Cut dough in half. Flour a board and roll dough out onto two baking sheets. Brush with remaining olive oil, sprinkle rosemary leaves, chopped garlic and coarse salt over top. Bake 375 degrees for 30 minutes.