Try this world-famous German herb sauce. Refreshing, delicious and yet so simple, these are the characteristics of the original Frankfurter Grie Soß (as Frankfurt green sauce is colloquially known).
Wash the herbs. If necessary, remove the leaves from the stems and roughly chop them. Place in a deep bowl.
Add the yoghurt and crème Fraiche or sour cream to the herbs. With a hand blender, puree the herbs. Alternatively, you can chop the herbs very finely and then mix them in with the yoghurt-crème Fraiche mixture.
Peel the onion and cube very finely.
Add the onion cubes, olive oil, mustard and lemon juice to the mixture. Season with salt and pepper.
Allow the mixture to rest for an hour in the fridge or a cool place before serving.