"As early as 1651, François Pierre La Varenne describes a sauce similar to Hollandaise sauce in his groundbreaking cookbook Le Cuisinier François: "avec du bon beurre frais, un peu de vinaigre, sel et muscade, et un jaune d’œuf pour lier la sauce" - wikipidia
According to my extensive knowledge of the french language what he is saying is, "with the good french brew, of the vinegar, and mustard, my little Jane devoured all the sauce."
Well what a review from little Jane! If you can get any kid to devour a sauce of vinegar and mustard I say props to the guy! After tasting this sauce I'm with Jane. This is the sauce on one of my favorite breakfasts - eggs benedict. I'm still perfecting the vegan'ised recipe but here is the sauce....Thank you Francois and little Jane!
basic white sauce
1-2 tsp mustard
1-2 tsp white vinegar
1 pinch paprika
Blend everything together. This sauce should be a light yellow in color and have a mild tang to it. Try this over vegan sausage or steamed asparagus.