Peel and wash the potatoes and cook in boiling salted water for 15-20 minutes. In the meantime, wash and clean the cucumber, cut it into thin slices, put it in a bowl and season with salt.
Carefully mix the cottage cheese with vinegar and sugar and fold into the cucumber slices, set aside. Wash parsley and dill, shake dry. Pluck the leaves or flags from the stalks.
Roughly chop the herbs and spread them on a flat tray. Drain the potatoes in a sieve. Heat milk in the pot, add potatoes and yoghurt, mash to puree and season to taste with salt. Cover the puree and keep warm.
Wash the chicken fillets, dab dry and season with salt and pepper. Heat the oil in a pan over medium heat. Fry the fillets for 8-12 minutes while turning. Lift out, turn in the herbs, press firmly and cut into slices.
Spread the puree and cucumber salad on the plates and place the meat slices on top.