For the pepper sauce, crush the peppercorns in a mortar. Peel and chop 4 shallots. Heat 2 tablespoons of butter in a saucepan. Sauté the diced shallots in it. Briefly fry the peppercorns. Dust with flour and sauté until golden brown.
Add wine and stock while stirring, bring to the boil and boil down for about 20 minutes. Season to taste with salt, pepper and lemon juice.
For the herb butter, wash all herbs, shake dry and chop finely. Knead with 100 g soft butter. Season to taste with salt and pepper.
Clean, wash and cut the leek into rings. Peel 8 shallots and chop finely. Peel garlic and cut into thin slices. Wash the tomatoes and leave on the panicles if necessary. Dab the fillet dry and cut into about 6 steaks (3-4 cm thick).
Heat the oil in a large frying pan. Fry the steaks on each side over a high heat for 1-2 minutes. Switch down to medium heat. Then continue frying for 2-3 minutes on each side for one pink steak (medium).
Season with salt and pepper. Take it out. Wrap in foil and let it rest for 5-8 minutes.
Sauté the shallots, leek, garlic and tomatoes in the cooking fat for approx. 5 minutes, stirring continuously. Wrap the steaks out of the foil and pour the resulting meat juice into the pepper sauce. Add the pepper sauce to the leek vegetables.
Place the steaks on top, spread herb butter on the steaks and fry everything else for another 2-3 minutes. Baguette tastes good with it.