Wash the potatoes and boil in water for about 20 minutes. Peel onion and garlic. Chop the onion roughly, chop the garlic. Wash parsley and chop finely, except for a little bit for garnishing
Quench the potatoes, peel them and let them cool down a little. Cut them into thick slices. Whip vinegar, salt, pepper, sugar, garlic and oil. Mix marinade with potatoes, onions, olives and parsley. Let the salad stand for at least 1 hour. Garnish with the rest of the parsley