At least 1 hour before baking, heat oven to 550°F (or 500°F if that's your oven's maximum temperature), with a baking steel or stone on the upper-middle rack.

Using an electric mixer, whip the cream until it holds stiff peaks. Fold in the fontina, Parmesan, ½ teaspoon pepper and ¼ teaspoon salt.

In a large bowl, whisk the oil, lemon zest and juice, and a pinch of salt. Set aside.

Dust a baking peel, inverted baking sheet or rimless cookie sheet with semolina. Transfer the first dough round to the peel and, if needed, reshape into a 10-inch circle. Using the back of a spoon, spread half of the cream mixture on the dough, leaving a 1-inch border around the edge. Using your fingers, crimp the outer ½ inch of the dough to form a raised edge to contain the sauce and cheese.

Slide the pizza onto the baking steel and bake until well browned and the cream mixture is bubbling, 7 to 10 minutes (9 to 12 minutes in a 500°F oven).

Using the peel, transfer the pizza to a wire rack. Repeat with the second dough round. After the second pizza has cooled for a few minutes, toss the arugula with the oil mixture. Top the pizzas with the arugula, dividing it evenly.