Place a cast iron pizza pan in over; preheat to 450F. In a sauté pan over medium heat, warm 1tbsp oil. Add onion; cook stirring occasionally, until tender, about 5 min. Season with salt and pepper; transfer onion to bowl. Roll out dough into a 12" round. Lightly dust a baking peel with cornmeal; lay dough on top. Lightly brush dough with oil; spread onion on top, leaving a 1/2" border. Scatter goat cheese over onion. Scatter asparagus on top.; season with salt and pepper. Sprinkle with Parmigiano-Reggiano and half the oregano. Slide pizza onto preheated oven pan. Bake until bottom of crust is golden and cheese is bubbly, about 15 min. Remove pan from oven; arrange prosciutto on pizza, sprinkle with remaining oregano and drizzle with a little oil. Let cool 5 min. before serving.
