Steam the broccoli, mushrooms, zucchini, and peppers for 10 minutes.
Saut� the onion and garlic over medium heat and mix with the steamed vegetables.
Combine the butter, evaporated milk, and Parmesan cheese over moderate heat until thickened and heated through. Stir continuously to avoid scalding. Remove from the heat and keep warm.
Cook the pasta according to package directions.
Serve the pasta with the vegetables, sauce, and fresh parsley.