Wash potatoes and cook 15-20 in boiling water. Then rinse with cold water, peel and leave to rest. Meanwhile, wash the legs and dab dry. Season with salt and pepper. Mix sweet-sour sauce and mustard.
Brush clubs with it. Cook in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 30 minutes. Defrost the peas. Peel and halve the onion. Clean and wash the radishes.
Cut onion into fine strips, radish into slices. Cut potatoes into slices. Mix with onion strips. Bring vinegar and broth to the boil briefly. Season with salt, pepper, pink berries and sugar.
Pour hot over the potatoes. Cut the cress short. Mix potatoes, radishes, peas, cress and oil. Season again and serve with the chicken legs.