Make sure the kokum is cleaned of all grit, then soak in a bowl of warm water for 30 minutes.
Puree on a curry stone or in a blender then transfer to a non-metallic bowl if not using immediately.
Put the gram flour in a small bowl, add 2 tablespoons coconut milk and soak until required.
Put the green chillies, ginger, cumin seeds and asafoetida in a small blender or food processor and process until ground.
Mix all the ingredients, except the seasoning, together in a large, heavy-based pan and bring to the boil just once.
Heat the ghee for the seasoning in a small frying pan (skillet) over medium heat, add all the ingredients and stir-fry for 1 minute.
Pour over the curry, then stir well and remove from the heat.