Clean the beans, wash them. Put the beans in boiling salted water and cook for 12-15 minutes. Drain, rinse with cold water and drain well. Peel and finely dice onions
Whisk vinegar, salt, pepper and sugar. Fold in a thin stream of oil. Mix beans and onions with the vinaigrette. Leave to stand for at least 1 hour. Season to taste once again. Wash the parsley and dab dry. Remove leaves and chop finely. Sprinkle salad with parsley
Waiting time approx. 1 hour