|Dry mustard||2 Tablespoon|
|Egg||1 , beaten|
|Whipping cream||1⁄2 Cup (8 tbs)|
|White wine vinegar||2 Tablespoon|
Mix together in a small saucepan the dry mustard, sugar, water, and vinegar.
Add the butter and cornstarch.
Stirring constantly, cook until sauce comes to a full rolling boil and is thick and clear.
Stir sauce into the beaten egg, return to pan, and cook, stirring constantly, 2 or 3 minutes longer, until thick do not let boil.