Put the kidney beans in a sieve, rinse under running water and free from their own juice. Cut the feta into small cubes and place in a bowl with the kidney beans. Cut off the lower 5 centimeters of the leek and then wash the individual leek leaves well so that there is no more soil or the like on it. Then cut the leek into small leaves about 1 by 1 cm and add to the feta in the bowl. Mix oil, vinegar, water, sugar, salt, pepper and, if you like, finely chopped parsley to a sauce, pour over the salad and stir everything well.
The salad tastes best when it is steeped in the refrigerator for 2 to 3 hours.
If you prefer the dressing a little more spicy, a bag of ready-made dressing Italian style or Paprika Herbs (both with the addition of 3 tablespoons of oil and 3 tablespoons of water per Bag of dressing).