1/4 c. sugar
2 egg yolks
2 tbsp. dry mustard
1/3 c. vinegar
1/2 pt. heavy cream

Mix egg yolks and mustard with vinegar. In double boiler stir half of cream with the yolks, mustard, vinegar mixture and sugar. Cook and stir until it thickens a little.

Chill in refrigerator. Beat the rest of the cream and fold in the cooked mixture when completely cool.