Spray a large skillet with cooking spray. Sauté steak over medium-high heat for about 3-5 minutes per side, or until it is cooked to your liking (keeping in mind that steak will continue to cook slightly once removed from the heat). Keeping skillet hot, transfer steak to a cutting board and allow to rest for about 10 minutes (this allows the juices to settle into the meat so they are not lost in cutting). Cut steak across the grain into thin slices.
Add peppers and mushrooms to hot skillet. Sauté until tender (3-5 minutes).
Add slices steak, cooked pasta, asparagus and alfredo sauce to cooked peppers and mushrooms. Cook until evenly heated (approx. 2-3 minutes), stirring constantly, taking care not to boil it.
Season with pepper. Top each serving with parmesan (if using).