Peel the sausages, cut into thin slices, and place in a bowl. Peel and halve the red onion, and cut into fine slices. Wash and slice the radishes. Peel the cucumber, and cut it into quarters lengthwise. Remove the seeds, and cut the quarters into small pieces. Wash and quarter the cherry tomatoes. Add to the sausages along with the other sliced vegetables.
To male the dressing, peel the white onion, cut it in half, and slice it into fine strips Heat the oil in a pan, add the onion, and cook for 4-5 minutes at low heat, Sprinkle sugar over the onion, and allow it to caramelize.
Pour the warm vegetable broth over the onion, and stir in the mustard and vinegar. Peel and finely chop the garlic, and add to the dressing. Cook for 8-10 minutes at low heat. Season with salt and pepper.
Let the dressing cool to lukewarm, and pour over the salad. Blend thoroughly, and allow to steep for at least 10 minutes. Garnish with chopped chives and serve.
Our tip:
Regensburg sausages are small and thick, and made of pork; they are not widely available outside of Bavaria. Instead, you can use bologna (which is similar to German Fleischwurst) cut into strips.