Mustard Sauce

Directions

1. 1
   Mix mustard and vinegar until smooth and then let stand overnight.
2. 2
   Mix egg, sugar and salt.
3. 3
   Blend with mustard mixture. Cook over low heat, stirring constantly, until mixture starts to thicken (about 20 minutes).
4. 4
   The longer you cook it the thicker it becomes.
5. 5
   Cool completely after mixture has reached desired thickness, then blend with mayonnaise.