Stir the vinegar, lemon juice, mustard, herbs and spices into the oil. Crush the garlic well and add it too.
Put the steak together with the marinade in a freezer bag, massage the marinade evenly into the meat and seal the bag. Marinate for 12-18 hours in the refrigerator.
Take the meat out of the fridge at least 2 hours before preparation, dab the marinade and cover with cling film.
Heat a grill pan intensely, fry the meat for approx. 3 - 4 minutes, turn and fry on the other side for another 2 - 3 minutes. Pierce a roasting thermo at an angle at the thickest part of the meat and remove it from the pan at a core temperature of 56 ° C. Let rest on a wooden board for about 10 minutes and cut into slices across the grain.
If necessary, grind some black pepper over the meat.