Fettuccini Alfredo with Grilled Chicken

1 cup butter or margarine at room temperature
1/2 cup heavy cream
1/2 cup grated Parmesan cheese
1 pound cooked fettuccini pasta
parsley, to garnish
salt and pepper to taste
8 (3oz.) chicken breasts
Put margarine in a mixing bowl. Beat until light and fluffy. Add cream a little at a time and mix until well blended. Add cheese by tablespoon beating well after each addition. Prepare fettucini according to directions on the package. Drain. While pasta is still hot pour sauce over pasta. Toss lightly until well blended. Add salt and pepper. Grill Chicken breasts. Slice into bite size pieces and place on top of pasta. Garnish with parsley. Serve while hot.