Wash potatoes thoroughly, peel and slice them. Peel and chop the onion. Heat 1 tablespoon of oil in a saucepan and fry the onions until transparent. Add the potatoes, fry briefly and deglaze with stock. Bring to the boil, cover and cook over medium heat for about 10 minutes. In the meantime wash, peel and slice the cucumber.
Clean and wash spring onions and cut them into rings. Wash the meat and dab dry. Whisk egg and cream. Mix breadcrumbs, flour, salt and pepper. Pour potatoes on a sieve, catch stock. Measure 150 ml stock. Mix stock, vinegar, salt, pepper and sugar. Add 2 tablespoons of oil. Mix cucumber slices, spring onions and potatoes and pour the lukewarm vinaigrette over it and mix carefully. Heat the remaining oil in a frying pan. Turn each cutlet first in egg and then in the breadcrumbs. Put them into the pan and fry them on each side for 2-3 minutes at medium heat.
Mix stock, vinegar, salt, pepper and sugar. Add 2 tablespoons of oil. Mix cucumber slices, spring onions and potatoes and pour the lukewarm vinaigrette over it and mix carefully. Heat the remaining oil in a frying pan. Turn each cutlet first in egg and then in the breadcrumbs. Put them into the pan and fry them on each side for 2-3 minutes at medium heat. Arrange potato salad and schnitzel on plates. Serve garnished with radishes and chervil as desired