Wash the potatoes thoroughly and cook covered in water for about 20 minutes. Pour potatoes into a sieve, steam well and let cool.
Meanwhile, for the yoghurt sauce, wash parsley and chives and shake dry. Remove the parsley leaves and chop them finely. Cut the chives into fine rolls. Mix sour cream, yoghurt and herbs.
Season to taste with salt and pepper.
Peel and finely dice the shallots. Mix with vinegar. Season with salt, pepper and sugar. Wash and halve the tomatoes. Cut the fat edge off the meat. Dab the meat dry and cut into wafer-thin (!) slices.
Wash the basil, shake dry and remove the leaves.
Mash the potatoes flat. Heat 1 tablespoon of clarified butter in a large pan. Fry 4-5 potato escalopes in it on each side for 2-3 minutes until crispy. Season with salt, a little pepper and chili flakes.
Remove and keep warm in a hot oven. Fry the remaining potato cutlets in the remaining clarified butter and season as well.
Heat the oil in a large pan (preferably a cast-iron pan) until it is very hot (may be just before smoking). Fry the meat in it in small portions at high heat for 45 seconds, turning once.
Season with salt and pepper. Take it out immediately, even if it is not roasted all around - it will recook.
Add the tomatoes to the hot frying fat and toss briefly. Put all the meat back into the pan. Add shallots vinegar and basil. Mix everything. Take it off the stove. Arrange potato cutlets and lukewarm steak strips.
Add yoghurt sauce.