1/2 cup Sugar =OR= Sugar substitute
1/4 cup Mustard -- dry, PLUS
1 tablespoon Mustard -- dry
1/2 teaspoon Salt
2 tablespoons Flour -- all-purpose
1 cup Milk
1 Egg yolk
1/2 cup Vinegar

Combine sugar, mustard, salt, and flour in a small saucepan; stir well. Combine
remaining ingredients; beat well. Gradually add milk mixture to mustard mixture;
cook over low heat, stirring constantly, until thickened and bubbly. Cool
thoroughly, and store in refrigerator.