The fillet with dark chocolate sauce is a second dish of great refinement, which can also be proposed as a main course for a lunch or for a very gourmet dinner!
Prepare the sauce:
warm the butter and simmer the finely chopped shallot in the fire, then combine the crumbled beer and cocoa so that they do not form snails and leave to thicken for about 10 minutes. Adjust the sale and pepper and pass to the sieve. Keep warm.
Apart, season the meat with oil, salt and pepper and pass into a hot pan. Bake a few minutes on the side with a lively focus, preferably in a pot of iron or cast iron. Spread on a cut, cut a slice and place on the pot plate, then jump generously with the sauce.
Dust with finely chopped pistachios and serve immediately.