Flour, mustard powder, sugar and salt to combine in bowl. Drive egg, stir until smooth and enter the vinegar.

A lot cook in a water bath until thick, stirring constantly with a whisk. This will take 3-4 minutes. Remove from heat and leave to cool.

In the cooled mass to enter the cream (fat content at Your discretion). The cream can be partially replaced with milk, but not more than 1-2 tablespoons, you can also add a few tablespoons of milk if the sauce is too thick. Try the sauce to taste, if necessary add a few drops of lemon juice. The sauce should be quite thick and rich taste.

Refueling can be stored in a tightly sealed container in the refrigerator for 1-2 weeks. The basis of the recipe taken from the book of Gary Rhodes New Classics. Bon appetit!