1 box fettuccine
1/2 c. butter
2/3 c. sour cream
3/4 c. grated Parmesan cheese
1 egg yolks, slightly beaten
1 tbsp. parsley, chopped

Cook fettuccine. Melt butter in saucepan. Add sour cream, Parmesan cheese, egg yolk and parsley. Cook until hot. Pour over cooked fettuccine and toss.