You add the arugula and the salad after the base is cooked. Some places cook it with sauce only and add shredded uncooked mozzarella, some cook it with minimal cheese on the pie and add the shaved cheese on the salad. Dealer’s choice.

Edit: bf is insisting the no cooked cheese is best, with a light vinaigrette. I think it’s worth playing around with it. But a lil dressing is nice.