Servings: Makes 2 pizzas
Preheat the oven to 450°.
Place the portobello mushroom on a heavy baking sheet. Drizzle 1 teaspoon of oil over the mushroom.
Bake for about 10 minutes, or until the mushroom is tender and its juices exude. Cool the mushroom then cut it into 3/4-inch slices.
Combine the mushroom strips and any accumulated juices in a bowl. Season the mushroom strips to taste with salt and pepper and set aside.
Lightly dust a countertop with flour and press 1 ball of dough on the countertop into a thin, round disk that is about 9 inches in diameter. Once the pizza dough is formed, lightly dust a baking tray with flour or cornmeal and place the dough on the baking tray.
Spread 1/2 the pesto in a thin layer over the dough, leaving a 1/2-inch border around the edge. Arrange half the mushroom strips and artichokes over the pizza. Sprinkle half the cheese over the pizza.
Place the pizza in the oven and bake for about 10 minutes, or until the bottom is crisp and deep golden brown and the cheese has melted and become pale golden on top. Remove the pizza from the oven and transfer to a cutting board. Repeat with the remaining ball of pizza dough, pesto, mushrooms, artichokes and cheese.
Drape the prosciutto over the pizzas. Scatter the arugula over the pizzas, then drizzle with the remaining 2 teaspoons of oil. Cut each pizza into 4 to 6 slices and serve.