Prepare the Dough: In a large mixing bowl, combine the warm water, active dry yeast, and a pinch of sugar (optional, to activate the yeast). Let it sit for 5-10 minutes until it becomes foamy.

Mix the Dough: Add the flour, salt, and 2 tablespoons of olive oil to the yeast mixture. Stir with a wooden spoon or a spatula until a shaggy, wet dough forms. Turn the dough out onto a lightly floured surface and knead for about 5-7 minutes until it is smooth and elastic. The dough will be slightly sticky.

First Rise: Transfer the dough to a clean, lightly oiled bowl. Cover the bowl with plastic wrap or a clean kitchen towel and let it rise in a warm place for 1-1.5 hours, or until it has doubled in size.

Prepare the Pan: After the first rise, generously grease a 9x13 inch baking pan with olive oil. This is a crucial step for achieving a crisp bottom crust.

Shape the Dough: Gently deflate the risen dough and transfer it to the prepared pan. Use your fingertips to gently press the dough to the edges of the pan, dimpling the surface with your fingers as you go.

Second Rise: Cover the pan again and let the dough rise for another 30 minutes. The dough should be light and airy.

Add the Toppings: Preheat your oven to 180°C (360°F). After the second rise, generously drizzle the top of the dough with more olive oil. Sprinkle the shredded mozzarella cheese and the chopped fresh green onion evenly over the surface.

Bake: Bake at 180°C (360°F) for 25 minutes, or until the top is golden brown and the cheese is melted and bubbly.

Finish and Serve: Remove the focaccia from the oven and let it cool in the pan for a few minutes. Before serving, sprinkle with a handful of fresh herbs. Slice into squares and enjoy warm or at room temperature.