Sauce Entrecote

Chop the shallot, melt it over low heat in a small saucepan with a little butter, for 2 to 3 minutes from the sizzling butter, but above all without grilling them. Then add the rest of the butter in pieces; melt slowly (the butter should hardly heat up). As soon as the butter is almost melted, remove the pan from the heat and add the rest of the herbs, the pepper, the nutmeg, the capers, the walnuts and the anchovies (and therefore not the mustard, the lemon, the English sauce or the yolk. egg). Pass everything through the blender in the special container supplied with your mixer, otherwise, in a container that is barely larger because mixing a small quantity is difficult in a container that is too large. This first step can be done up to 2 days in advance, and the temporary sauce stored in the pan in the refrigerator can be reheated over low heat before moving on to the final step. Final step Place the mustard, egg yolk, lemon juice and English sauce in a bowl. Mix so that these ingredients come to the same temperature. Cook the meat over high heat in a little peanut oil. One and a half minutes on each side in a very hot pan for rare cooking. Be careful, if you do not have a very strong fire, cook the meat in two batches so that it is well seared. Once the meat is cooked, remove the serving dish from the oven and the plates, place the meat on it and cover it with aluminum foil for at least 3 minutes so that it relaxes. Return the dish to the oven with the door half open to keep it warm; this stage of relaxation of the meat is fundamental for a meat cooked uniformly and not dry on the outside and bloody and cold in the heart if it is served immediately after cooking. While the meat relaxes in the open oven , assemble the final sauce in a bowl, such as mayonnaise, gradually adding the mixed sauce to the bowl containing the mustard while beating with an electric whisk. If you reheated it after keeping it in the fridge, make sure it isn't hot, just lukewarm. Once the sauce has been mounted (it has the consistency of mayonnaise), pour two-thirds of it into the pan. Prepare a container (a large dish or your sink) with 2 inches of cold water. Do not forget ! Heat the sauce in the saucepan, stirring until it begins to turn (it crumbles) but especially not boil, then immediately place the saucepan in cold water and continue to stir to stop the cooking. After a good 30 seconds, add the contents of the saucepan to the third of the sauce that was left in the bowl and beat with a whisk to partially bind the sauce and obtain the desired consistency. If you notice lumps, you have reheated the sauce too hard or too long and the egg has cooked. If the sauce is too smooth, you have not heated enough. Either way, the taste is the same.Salt (to be adjusted at the end because the salt intake of the anchovies is variable) https://www.atoute.org/n/Recette-de-la-sauce-entrecote.html