Mash all lumps out
of mustard--then measure. Make a smooth paste of mustard & vinegar,
and let stand overnight. Next morning, beat the eggs until
light, add sugar to them and beat until dissolved. Combine
mustard & vinegar mixture with eggs & sugar. Mix well & cook
in double boiler until it thickens.
Stores as well in refrigerator
as any prepared mustard from market shelves.