Wash the potatoes carefully. Cook in boiling salted water for 15-20 minutes. Then let them cool down and cut them in half, depending on size. In the meantime clean, wash and cut the beans into small pieces. Cook in salted water for about 15 minutes and drain. Clean and wash the tomatoes and cut them into slices. Clean, wash and roughly chop the rocket.
Season vinegar with salt, pepper and sugar. Gradually fold in the oil. Mix prepared salad ingredients and marinade. Cover and let stand for about 20 minutes. Slice cheese and fold in. Season again and serve in portions