Wash the potatoes and cook for 20-25 minutes in plenty of boiling water. Bring stock and vinegar to the boil. Drain potatoes, rinse briefly under cold water, peel and slice.
Add stock and vinegar to the potatoes. Let the salad steep for a short time. Wash and chop the parsley. Wash and halve the tomatoes. Wash, clean and slice the cucumber. Mix yoghurt and mayonnaise, season with salt and pepper.
Fold the cherry tomatoes, cucumber and chopped parsley into the potatoes. Season the salad again with salt, pepper and possibly a little vinegar. Put the sausages in boiling water and let them simmer for about 5 minutes.
Serve the sausages with the potato salad.