Wash the mint and pluck the leaves from the stems. Put this together with the olive oil in the food processor to chop it up until it has a consistency like paste (if necessary, a strainer works too). Make sure that the mixture is not too dry, otherwise add a little olive oil if necessary.
Season with salt and pepper and then stir in the yogurt until the sauce is evenly mixed with the paste. If you like it, you can also add a few drops of lemon.
The sauce tastes best when you chill it for 24 hours and let it steep. Then the aroma and taste develop much better.