Cook noodles al dente and set aside in a colander. Blanch the asparagus in boiling water for three minutes and rinse in cold water. Heat the olive oil in skillet and add the onion. Cook, stirring, until the onion softens, about 5 minutes. Remove from the skillet. Add the mushrooms to the skillet, cover and cook on low heat for 3 minutes. Uncover and cook until all the liquid is absorbed. Return the onion to the pan, and add the lemon juice, basil, and asparagus, and cook until warmed through.
Add the noodles to the pan and toss with black pepper and Parmesan cheese. Toss until the noodles are warmed through before serving.