For the Beef Carpaccio with Porcini, first rinse the beef tenderloin in a cool place and dry.
Using a large sharp kitchen knife, cut the meat into very thin slices. Lay out four plates with the washed lettuce leaves, place the filet slices on them and drizzle with the olive oil.
Clean the mushrooms, rub them with a wet utensil and cut them into thin slices. Place on the slices of meat and drizzle on the spot with the juice of a lemon.
Finally, season the beef carpaccio with porcini mushrooms with ground pepper and salt, if desired.