Put the herbs in a food processor along with the chillies, salt, sugar, lemon, 1 tbsp water and 2 tbsp yogurt. Blend really well to make a green paste. Tip into a bowl.
Spoon off 4 tbsp and mix with the rest of the yogurt to make raita. Cover and chill both overnight.
How to BBQ poppadums
Use tongs to hold a poppadum over the BBQ for just a few secs until it puffs up. Alter the position of the tongs to ensure it cooks evenly.