Method

1. Crush the chilli, turmeric, white turmeric, curry leaves, fresh coriander, Rajah cumin seeds and pigeon peas together with a pestle and mortar (or in a blender) to make a fine masala paste.
2. Whisk the yoghurt and chickpea flour together in a large pan to combine, then add water and whisk (or blitz with a handheld blender) until smooth.
3. Place over medium heat and stir in the masala paste, salt and sugar. Cook for 4-5 minutes, stirring continuously to ensure that the yoghurt doesn’t split, then remove from the heat.
4. Heat the oil in a small pan or frying pan for 30 seconds over a medium heat, then add the Rajah red chilli. Once it starts to turn darker (after about 30 seconds), add the Rajah cumin and Rajah mustard seeds. As soon as the Rajah mustard seeds start to pop, add the curry leaves and then the coriander.
5. Slowly and carefully pour a ladleful of the yoghurt mixture into the pan, a little at a time. Stir through, then pour the contents of the pan into the large pan containing the rest of the yoghurt mixture and stir to combine.
6. Stir through then remove from the heat and leave to rest covered for at least 10 minutes.