2 sticks butter
2/3 c. half and half
2 egg yolks
Pasta (cooked)
1 c. Parmesan cheese
2/3 c. sour cream
Parsley

Melt butter in pan over low heat. Remove from heat and gradually add Parmesan cheese, half and half, sour cream and egg yolks (slightly beaten). Toss over hot pasta and add parsley.