Apologies for having a second question today, I wouldn't have asked if there hadn't been so many great ideas for the potato salad!
Anyway, this is for a salad dressing, again used to eat it in Stuttgart. I can't remember much about it except it was green (helpful I know) and you could make it in bulk. It was sharp so must have had vinegar in it but not thin so it wasn't a vinaigrette. I'm pretty sure dill was involved.
We used to have it in avocados (cut in half and plop the dressing in the middle where the stone used to be).
I know it's a long shot but does anyone with any German connections have any idea what it might be?