1 1/2 c. half and half
1 1/2c. fresh grated Parmesan cheese (about 5 1/2 oz.)
1/2 c. butter
2 egg yolks
Salt to taste
Pepper to taste
3/4 - 1 lb. fettuccine noodles, cooked & drained
Sauteed mushrooms (optional)
Clams (optional)

Heat half and half in heavy bottom saucepan. When it is just beginning to simmer, stir the cheese into it, bit by bit. Continue stirring constantly over low heat for 10 minutes, then add butter a little at a time. When butter is incorporated and sauce is smooth, remove from heat and eat a small amount of sauce into egg yolks. Return egg yolk mixture to sauce and stir it in thoroughly. Season to taste with salt and pepper. Return to heat if necessary to thicken. Add mushrooms or clams, if desired.