Wash potatoes and boil or steam until tender, about 20 minutes.
For the dressing, bring the vegetable stock to the boil once and mix with balsamic vinegar, salt, pepper and sugar and season to taste. Allow the cooked potatoes to cool briefly, then cut in half and marinate with the dressing while still warm.
Peel the onions, wash and clean the radishes and cut both into fine slices. Drain the capers well. Wash and roughly chop the herbs. When the marinated potatoes are only lukewarm, add the vegetables, herbs and oil, mix loosely and season again.
Fry the veggie schnitzels with sufficient oil over medium heat for a total of about 4-5 minutes on both sides until golden brown.
Pro tip: The potato salad can also be easily modified by adding pesto instead of the vegetables, or pumpkin seeds and pumpkin seed oil.