This sauce is one of my favourites, as you will see by the number of times I use it to accompany various dishes in this book. It has its origins in India and is known there as podina, of which there are many varieties and interpretations. It goes particularly well with fried food, spiced meats and pastries.
Chop herbs and chillies. Blend all ingredients except yoghurt to a paste in a food processor. Add yoghurt and pulse only until mixture comes together. Do not overwork or yoghurt will split and make the sauce too thin. Refrigerate for up to 2 days.