White Wine Sauce - cooking recipe

Ingredients

1 Tbsp. butter or margarine
1 Tbsp. flour
dash of salt
2/3 c. milk
1 egg yolk, beaten
2 Tbsp. to 1/4 c. white wine or sherry

Preparation

Melt butter in small pan; blend in salt and flour.
Gradually add milk, stirring constantly.
Cook until thick.
Remove from heat and stir small amount of mixture into beaten egg yolk and return to hot mixture.
Bring just to a boil, stirring constantly. Remove from heat and stir in wine.