Cook asparagus and pasta in boiling water 3 minutes or until the pasta is done. Drain asparagus and pasta in a colander over a bowl, reserving 1/2 cup cooking liquid.
Wipe pan dry with a paper towel. Heat oil in pan over medium heat. Add onion and garlic; cook 2 minutes, stirring frequently. Add prosciutto; cook 2 minutes, stirring frequently. Stir in asparagus and pasta, reserved cooking liquid, vinegar, salt, red pepper, and black pepper; toss well. Sprinkle with Parmesan cheese.