Wash the potatoes and cook for about 20 minutes. Drain, rinse with cold water and remove the skin. Let the potatoes cool down. In the meantime peel onions and cut them into rings. Clean, wash and slice the radishes. Cucumbers and potatoes also cut into slices. Mix the prepared ingredients.
Heat 1/8 litre cucumber water. Pour over the salad ingredients and leave to stand for a while. Mix mustard and vinegar. Season with salt, pepper and sugar. Whip the oil into the mixture. Pour over the salad and mix everything carefully
Waiting time approx. 30 minutes