Mix dry mustard and vinegar and let stand overnight in a closed container. I use a glass mason jar and lid.

The next day, in a glass saucepan beat egg; mix in sugar, salt and mustard mixture; cook over low heat, stirring constantly with wire whisk, until mixture thickens and just begins to bubble.

Take off heat. Let cool approximately 30 minutes; then stir in miracle whip.

Keep in a sealed container in the refrigerator.

Will keep in the refrigerator for up to two months.

Notes: This mustard is perfect with ham. Great sandwich spread. It also works well as a dip for sausage or pepperoni sticks at a party.