Mustard Sauce
["1/2 c. Coleman's dry mustard", "1/2 c. white vinegar", "1 egg yolk, beaten", "1/3 c. sugar", "1 c. mayonnaise"]
["Mix dry mustard and vinegar and let stand for 1 hour.", "Add beaten egg yolk and sugar.", "Cook over medium heat in saucepan until thick, stirring constantly.", "Cool and add mayonnaise.", "This will keep refrigerated for a long time."]
["mustard", "white vinegar", "egg yolk", "sugar", "mayonnaise"]