1 pkg. fettuccine
1/2 c. Parmesan cheese
2/3 c. light cream (or 2/3 c. sour cream)
1/4 lb. sweet butter
1 egg yolk

Cook noodles. While noodles are cooking, beat egg yolk lightly with a fork. Add to cream. Melt butter and mix altogether, adding cheese (use whisk). Drain noodles and pour mixture over noodles. Toss with fork and spoon until well blended. Top with additional cheese, if desired. Serve immediately.