1 lb. fettuccine noodles, cooked al dente
1/4 lb. butter
1 egg yolk
1/4 c. heavy cream
1/2 c. freshly ground Parmesan cheese
Salt & pepper to taste

Cream butter until fluffy. Add egg yolk and cream; beat constantly while adding cheese a tablespoon at a time.

Put drained noodles in a large bowl. Add cheese mixture to fettuccine and season as desired with salt and pepper. Prepare just before serving as it should be served immediately.