In lg plastic, resealable bag, place chicken in flour. Shake to coat. Heat 2 tsp oil in lg skillet over medium heat. Cook chicken in oil for about 5 mins per side, till browned.
Place chicken in a lg bowl. Cook pasta as directed, drain, reserving 2/3 cup cooking water. Put pasta back into pot.
Heat remaining oil in same skillet. Add all peppers, onions and garlic. Cook, stirring for 3 mins. Cover, reduce heat to low and cook until veggies are tender. Stir in alfredo sauce. Add sauce and veggies to pasta w. reserved liquid. Toss to coat. Sprinkle w/ parsley. I serve w/ freshly grated parmesan cheese, but that's optional.