Wash the cucumber, do not peel it and dice it as big as the carrot. Peel the onion into small cubes and fold it into the potatoes together with the cucumber and chives. Mix the marinade with the vinegar, oil, pepper, salt and sugar and mix it thoroughly with the other ingredients. The salad should be prepared in the morning for the evening. So he can pull off really well. If it is used as a lunch meal, preparation the evening before would be ideal. Before serving, try again and, if necessary, add all the ingredients in the marinade.