Steak frites sandwich with L'Entrecôte-style sauce

Melt some butter over low heat without browning it.

Add the chopped shallot and cook a couple of minutes until translucent, without browning.

Add the rest of the butter and melt it, no browning.

Add tarragon, parsley, basil leaves, anchovies in oil, capers, whole walnuts, a decent amount of pepper and nutmeg; mix.

Kill the heat and blend smooth with a hand mixer, in a taller, narrower vessel to avoid splattering.

Beat an egg yolk with about a tablespoon of Dijon, a teaspoon of Worcestershire and about the same of lemon juice until smooth and slightly thickened; mix in the blended sauce.

Return about two-thirds of the sauce to the pot and heat, sizzling a little at the sides, about a minute, until the fat starts to separate.

Take off the heat, cool about 30 seconds, add the remaining sauce and beat to bring the broken and unbroken together; keep aside and rewarm to serve.

Rub the ribeye with a little oil, season with kosher salt and pepper, and cook in a hot cast iron pan, flipping about every minute and a half.

Cook to medium-rare, pulling the steak between 128 and 130.

Fry store-bought fries three to four minutes, lift, then raise the heat and fry again just before serving.

Add a big knob of butter near the end and let it melt; pull the steak and rest it about 10 minutes.

Cut the baguette; slice the steak; load the steak into the baguette, then the fries, then plenty of the warmed sauce.