Hot Mustard

1 cup dry mustard

1 cup flour

1 3/4 cup vinegar

1 ¾ cup sugar

1 teaspoon salt

1/3 cup or less melted butter

Sift all dry ingredients together.  Bring vinegar to a good rolling boil. 

Add to dry ingredients, stirring constantly.  Add melted butter. 

If lumpy, put through sieve.  Let stand overnight before using.