Trim 1/2 pound asparagus. Cut each stalk in half lengthwise, then crosswise into 2-inch pieces. Form 1 pound refrigerated pizza dough (at room temperature) into an 11-by-15-inch rectangle on an oiled piece of parchment. Top with the asparagus and 1 cup shredded fontina. Slide the crust (on the parchment) onto a preheated pizza stone or inverted baking sheet. Bake at 475˚ until the bottom is crisp, 12 minutes. Top with pesto and red pepper flakes.