Wash the potatoes and cook for about 20 minutes. Quench and peel. Cool down
Peel or clean and wash carrots, radishes and cucumber. Coarsely grate carrots. Radish and cucumber small, potatoes in slices cut. Wash and finely chop the chives.
Peel and finely dice the onions and fry them in 1 tablespoon of hot oil until transparent. Deglaze with 1/8 l water and vinegar and bring to the boil. Stir in broth, mustard and remaining oil. Season to taste with salt, pepper and sugar. Pour over the potatoes while still hot. Fold in carrots, radishes, cucumber and chives. Cover and leave to stand for at least 30 minutes.
Clean, wash and drain the arugula. Cut a little smaller. Wash the cress and cut from the bed. Add rocket to the salad and season to taste