Cook crushed tomatoes and a pinch of salt and pepper together over medium heat for 15 minutes. Stirring occasioanlly.
Press dough into a 12 inch seasoned cast iron skillet, brush with olive oil. Turn heat to medium and cook for 3 minutes. Spoon crushed tomatoes over the top, sprinkle with garlic, top with mozzarella followed by prosciutto.
Transfer to preheated oven and bake for 12 - 15 minutes or until cheese has melted, prosciutto is crispy and crust has browned.
Remove from oven, top with arugula, slice and serve.