1/2 lb. American cheese, grated or shredded
2 tbsp. Parmesan cheese, grated
2 egg yolks
1 tbsp. butter
1 c. milk
2 tbsp. very dry white wine
1 tsp. cornstarch

Place butter in top of double boiler. In the meantime, beat together egg yolks and milk with fork, then add to butter. Add grated Parmesan and shredded American cheese to mixture. Let water in pan come to boil. Stir cheese mixture with wooden spoon constantly until cheese and butter melt. Mix wine and cornstarch before adding to cheese mixture. Stir constantly until mixture smooths and thickens. Remove from boiling water and serve.

If necessary to reheat sauce, place over boiling water and stir constantly. Serves 4.