1 lb. pasta of choice (cook according to package)
3 tablespoons butter
8 fluid ounces heavy whipping cream
1 pinch ground nutmeg
1/2 cup grated Parmesan cheese
1 egg yolk
2 tablespoons grated Parmesan cheese
Melt butter or margarine in a saucepan over medium heat. Add heavy cream, stirring constantly. Stir in salt, nutmeg, grated Parmesan cheese, and grated Romano cheese.
Mix yolk with about 1/4 cup sauce, separately.
Add back in and heat to just a simmer.
Boiling will overcook egg yolk.
Garnish with additional grated Parmesan cheese, if desired.