In a medium size bowl, combine the water and sugar and add in the yeast, and let it sit for about 15 min.
Once the 15 minutes are over stir in the flour, salt and olive oil, and mix using your hands.
Take the dough out of the bowl and place it on a clean, floured surface, and start kneading it for 10 minutes.
Form a ball and place it in a bowl, with some oil, and cover it with a kitchen towel. Let it rest for 30 min. aprox.
Place the pizza stone in the oven and preheat to 482°F (250°C).
Take the dough out of the bowl and roll it out using a rolling pin and form a circle (it doesn´t have to be perfect). Sprinkle the garlic salt and oregano over it. Then grate some parmesan cheese on top and add some more olive oil.
Bake at 482°F (250°C) for about 10 to 15 min. or until the focaccia starts to turn golden, placing the focaccia on top of the pizza stone.