Preheat the oven to 200°C–220°C (fan).
Spread the tomato sauce evenly over the base, leaving a 1 cm border around the edge.
Add the mozzarella, cut into pieces.
Bake the base directly on the oven rack for 5–7 minutes.
Once out of the oven, top with the prosciutto slices and fresh arugula.
Sprinkle with a little oregano or fresh basil and serve immediately.