1 Scrub the potatoes, place in a pot and cover with water. Bring to a boil, cover and cook until potatoes are knife-tender, 20-25 minutes. Drain, rinse with cold water, peel and let cool on a plate.
2 Heat broth in a small pot just until warm (but do not boil). Season with vinegar, salt and pepper.
3 Cut the cooled potatoes into slices and place in the warm broth. Let stand 40 minutes.
4 Meanwhile, rinse the radishes and drain well in a sieve. Rinse the small, delicate radish leaves as well and shake dry.
5 Cut the radishes into thin slices, then cut crosswise into thin strips and combine with the tender leaves in a bowl.
6 Rinse the sprout mix in hot water and drain well.
7 Mix potatoes and broth with the radish strips and leaves. Season with salt and pepper, top with sprouts and serve.