This essence of zest is via Howard Mitcham, who claims he received it from Justin Galatoire, the nephew of Jean Galatoire, in the 1950s. We have no reason whatsoever to doubt he did.
1/2 cup Creole mustard
2 tablespoons vegetable or olive oil
2 tablespoons paprika
2 tablespoons white vinegar
2 tablespoons finely minced scallion or parsley
Hot sauce and horseradish to taste