Famous Paris Steak Sauce (Relais de l'Entrecôte)

Finely slice one shallot.

In a saucepan on low heat, slowly poach the sliced shallots in butter until they are soft.

Transfer the poached shallots and melted butter to a food processor. Add tarragon, parsley, sage, basil, anchovies, nutmeg, walnuts, capers, salt, and pepper.

Blend the mixture in the food processor until it is well combined.

In a separate bowl, combine one egg yolk, a teaspoon of Dijon mustard, Worcestershire sauce, and white vinegar.

While continuously mixing, slowly drizzle the blended herb butter mixture into the bowl to create a smooth emulsion.

Take two-thirds of the sauce and place it in a saucepan over low heat.

Cook the sauce, stirring, until it starts to look slightly grainy, then immediately remove it from the heat.

Add the remaining one-third of the sauce back into the pan and mix everything together off the heat.

Pour the warm sauce generously over sliced steak and serve with french fries.