Peel the cucumber and slice it into a bowl. Depending on your taste, you can leave the bowl on, but then wash it off well beforehand. Add the sugar. Chop the onion into small cubes and add. Add the vinegar and cooking oil and mix well.
Sprinkle the chives on top depending on your taste.
Put the salad in the fridge for about 3/4 hour so that everything can flow through. Mix again before serving.