This is a "TasteofHome" recipe that my whole family LOVES!!! Although I add more cheese and salsa, I am putting original recipe here. If you wish to add more or less of any ingredient feel free, however I would not use less Alfredo sauce!
In large skillet over medium heat, cook chicken, onion, green pepper and pepper in oil until chicken is no longer pink. Stir in Alfredo sauce; bring to a boil. Stir in 1-3/4 cups cheddar cheese, Parmesan cheese, salsa, milk and taco seasoning.
Drain pasta; toss with chicken mixture. Divide between two greased 8 inch baking dishes.
(Cover and freeze one casserole for up to 3 months, if recipe is too large.)
Cover and bake the remaining casserole at 350 degrees for 30-35 minutes or until bubbly. Sprinkle with remaining cheese.
To use frozen casserole: Thaw in refrigerator overnight. Remove from refrigerator 30 minutes before baking. Cover and bake at 350 for 50-60 minutes or until bubbly.