Cafe de Paris / Le Relais de l'Entrecote Sauce

I was in Geneva with a friend last week.  I am not a big meat fan, in fact, I almost never eat meat.  But there are certain places where I cannot resist the offer.  We had lunch at the famous Le Relais de L'Entrecote on Rue de Rhone.  The famous place as you might know serves one menu only:  A small salad with vinaigrette, followed  by an amazing piece of entrecote with their famous sauce and french fries.  The place has an interesting history.  You can read more about it here.

The sauce was so delicious that I quickly realized that I have been eating cheap fakes since the last time I had been to the restaurant's branch in Paris.  After this current Geneva experience, it was not going to be possible to eat cheap fakes anymore.  So I started searching everywhere for the recipe.  There are many out there.  The real one does not seem to have been disclosed yet, but a lot of devoted cooks and chefs have worked hard to develop their versions.  My humble version is below.  I was very happy with it, and so were my guests who have had a chance to try the original sauce both in Geneva and Paris.

I have to credit Scott and his blog Meats, Roots and Leaves for the base recipe which I modified.

1 tbsp olive oil
1 large onion, thinly sliced and chopped
3 cloves garlic, chopped
2 cups chicken stock (I used knorr brand bouillion)
1 tsp pepper
2 tbsp Dijon mustard
1 table spoon dried tarragon (fresh would have been better, but I couldn't find any)
2 table spoons chopped fresh parsley
1/4 cup white wine
4 tbsp unsalted butter
3 tbsp red wine vinegar
1 tsp anchovy paste
1 tsp Worcestershire sauce
1 teaspoon salt

Heat the olive oil on low heat.  Cook the onions and garlic for a few minutes on low heat until they soften.  Add the chicken broth, bring to boil, and simmer for 5 minutes.

While the broth simmers, place all other ingredients except for the butter in a blender.  Add the broth and blend everything into a smooth sauce.

Return to pan, add the butter, and continue to cook on low heat until the butter completely melts.

Pour on your steak and devour.  It's important to keep the sauce warm.  This is why they serve only a little bit a time on a small place and keep the rest warm on tea lights at Cafe de Paris and Relais de L'Entrecote.