Boil the potatoes in their skins, mix large and small ones. Then the little ones are a little softer afterwards!
Dice the onion, sauté in plenty of oil until translucent and transfer to a large bowl. Put the mayonnaise with salt, pepper, parsley and a good dash of cucumber water, a pinch of sugar, mustard and tomato paste in the bowl and stir everything well. Can be a little liquid, the potatoes will soak up everything afterwards. Cut the cucumbers into very small pieces and add them, amount to taste, I always put almost the entire glass in!
Peel the cooled potatoes, cut them into thin slices and add them to the bowl. It doesn`t matter if the small potatoes disintegrate, that`s a good thing! Mix everything together carefully.
If the salad is to be eaten straight away, add to taste! It`s even better if it can steep in the refrigerator for one night. Then season to taste before serving.