Once the ragi mixture has cooled, add dahi to a bowl along with black salt, jeera powder, onions, green chilli, curry leaves and coriander. Whisk this well and then add the cooked ragi and remaining ½ cup water. Mix this well and add more water if required. Taste for salt and spice and adjust accordingly.
½ cup curd, ½ tsp black salt, ½ tsp jeera powder, 2 tbsp chopped onions, 1 green chilli, 3-4 curry leaves, 2 tbsp chopped coriander