1On meduim heat, put italian dressing and chicken into a deep skillet.. cook covered (it will splatter) and turn a few times. Reduce heat after it has cooked for several minutes on each side, Cook uncovered until dressing has reduced to a glaze. Set chicken aside on a plate to rest while you prepare pasta and sauce.
2Sautee onions,garlic and mushrooms in olive oil over medium heat until onions begin to caramelize.
Add to alfredo sauce in a sauce pan and simmer for 5-10 minutes.
3Coat prepared pasta with sauce, then slice chicken and place on top. Sprinkle with desired amount of parmesan cheese, and serve!