1 lb. Fettuccine noodles cooked al dente
1/4 lb. butter
1 egg yolk
1/4 c. heavy cream
1/2 c. freshly grated parmesan cheese
Salt and pepper to taste

Cream butter until fluffy. Add egg yolk and cream constantly while adding cheese a tablespoon at a time. Put drained noodles in a large heated serving bowl. Add cheese mixture to noodles and season as desired with salt and pepper. Prepare just before serving as it should be served immediately.