Focaccia

Bahan-bahan (24 porsi)

• 5 cups all-purpose flour, (spooned into measuring cup and leveled-off, plus more for kneading)
• 1 tablespoon sugar
• 1 packet (2¼ teaspoons) instant/rapid-rise yeast ((see note))
• 1 tablespoon + ¾ teaspoon kosher salt, (divided)
• 1¾ cups warm water
• ¾ cup extra virgin olive oil, (divided, plus more for oiling the bowl and drizzling on top)
• 1 tablespoon chopped fresh rosemary, (from several sprigs)