Heat olive oil in a wok over medium-high heat. Cook onions for a couple of minutes. Add asparagus, add prosecco, and cook for 5 minutes. Let liquid evaporate. Stir in parsley.
Synchronously, cook the linguine in a salted and seasoned water until al dente. Immediately before draining water, scoop half a cup of the cooking water and set aside. Drain pasta, toss it back in pan and add back the reserved cooking water.
Add the butter to the pasta and then asparagus mixture.