Wash the potatoes and cook for about 20 minutes. Quench, peel and let cool off
Clean, wash and halve the beans. Cook in boiling salted water for about 15 minutes. Drain
Peel and chop the onion. Boil up about 1/4 l water and broth. Add onion and vinegar. Cut potatoes into slices. Pour over with the hot stock. Fold in the beans. Leave everything to stand for about 45 minutes.
Wash the tomatoes, cut them in half. Wash the marjoram, remove the leaves, chop roughly.
Puree the feta cheese and salad cream. Stir in yoghurt and marjoram. Season to taste. Mix into the potatoes with the tomatoes