Lightly butter your slow cooker insert, then add the soup, cream cheese, broth and dressing mix to the slow cooker and mix, see you did not even need to dirty a bowl for this.
Stir in the chicken. Cover and cook on Low setting for 4-6 hours.
Now right after you turned on the slow cooker, heat a pot of salted water to boiling. When boiling, add the fettuccine and cook until just before before done. Drain and rinse, cover and place in the fridge.
About 45 minutes to an hour before serving, add the pasta from the fridge, and sprinkle in some spring onion or parsley, reserve a bit of spring onion or parsley for garnish, stir well and cover and cook for just long enough to heat the pasta through, 45 minutes to an hour.
Serve with spring onion or parsley sprinkled on top, and sprinkle with some Parmesan cheese to taste.