Wash the potatoes and cook in boiling water for about 20 minutes. Quench cold, peel, let it cool down a bit and cut it into slices. Heat the stock, pour over the potatoes and let it stand for about 1 hour.
In the meantime, clean and wash the spring onions and cut them into rings. Rinse matie cold and dab dry. Wash, quarter, core and cut apples into small pieces. Drain the potatoes and collect the stock.
Mix mayonnaise, yoghurt and stock. Season with curry, salt and pepper. Mix potatoes, spring onion rings, apple and curry mayonnaise. Arrange the salad on a plate, add the matie filets.