Pour warm water into a small bowl and stir in the yeast and sugar until dissolved. Let it stand for about 5 minutes to make sure that the yeast is activated. A thin layer of foam should appear on the top, indicating good active yeast.
Mix the flour and salt in a large mixing bowl. Add the yeast water and 2 Tbsp of olive oil. Mix well with your hands or a mixing spoon. Lightly flour a clean working surface. Form the dough into a ball; turn it out onto the working surface. Flour lightly the top of the dough and press down with the palm of your hand. Fold the dough over itself and press again. Continue to roll and press the dough for about 12 minutes or until the dough is smooth and elastic, adding flour only when necessary to keep from sticking.
Place the dough back into the mixing bowl. Rub the remaining olive oil all over the dough to keep moist while it is rising. Cover the bowl with plastic wrap, and leave in a warm place (about 75 degrees) for 2 hours or until it rises double in size.
Once risen, you can use the dough to make pizzas, and or the remaining dough can be refrigerated for up 2 days. Roll the dough out on a lightly floured surface working it into a circular crust about 10 inches in diameter.
INDOOR: Wipe the bottom of a grilling pan or heavy bottom skillet with a paper towel moistened with olive oil. Preheat the pan over high heat for 5 minutes. Place the dough in the skillet. The crust should bubble on top within 1 minute; if not, turn the heat up.
OUTDOOR: If your using an outdoor grill, simply heat the grill to medium heat and place the dough on the grill, it should bubble and the crust should form.
Place the grilled pizza a working surface, grilled side up. Brush the grilled side of the pizza with olive oil. Top the pizza with the fresh mozzarella, then the arugula. Place the slice of prosciutto on the pizza in loose bunches, creating an alternating pattern. Finally top with the crumbled Gorgonzola, and return to the grill to grill the bottom of the pizza and until cheese is bubbling and the edges are golden brown. Serve hot.