A very simple basic sauce that can also be changed in a variety of ways.
Mix the mustard with the balsamic vinegar. Add yogurt and season with salt and pepper.
That`s it, but:
Here you could also mix in herbs, onions, Knofi or whatever else you like.
Just be careful, if you just double that, then I would be a little more economical with the mustard and not necessarily add another tablespoon per person to the vinegar!