Caramelize onions by heating 1-2 tablespoons of oil in a heavy-bottomed pan or Dutch oven over medium-low heat. Heat, stirring often, for 30-40 minutes or until the onions are deeply caramelized. Add a tablespoon of water to the pan occasionally if the onions are sticking to the bottom.
Preheat the oven to 500°F. Grease a sheet pan with one tablespoon of olive oil.
If using pizza dough, stretch it into 4 small pizzas or one large pizza and place it on the oiled pan. Oil the crust with the remaining olive oil.
If using naan or pita bread, place them on the pan and brush the bread with the remaining oil.
Spread the caramelized onions over the dough or bread and sprinkle the onions with arugula.
Peel the sliced prosciutto from the package and arrange small bundles of it over the arugula.
Tear the mozzarella into small pieces and place over the pizzas. Sprinkle the pizzas with black pepper.
Bake the pizzas for about 10 minutes, checking after 8 minutes. Broil the pizzas if desired.
Sprinkle with additional arugula leaves and serve.
Nutrition facts are sometimes provided below and are calculated using an online calculator. With specific brands of ingredients and additions, omissions, or substitutions the nutrition facts may change. We encourage you to use your own nutrition facts calculator to obtain the most accurate nutrition facts for your meal.