Bring a large pot of lightly salted water to a boil. Add noodles and cook for 7 to 8 minutes or until almost al dente (until ALMOST cooked); drain.
Preheat oven to 350 degrees F (175 degrees C).
Add the chicken, peas, soup, whipped topping, American cheese, milk, parsley, salt and pepper. Mix together and transfer mixture to a 9x13 inch baking dish. Sprinkle with Parmesan cheese and cover with aluminum foil.
Bake in preheated oven for 45 minutes, then remove cover and bake for another 10 minutes. Let cool for 4 to 5 minutes, allowing cheese to thicken slightly.