Preheat a frying pan and heat the rava till it becomes light brown and keep it aside.
Take a kadai or pan and heat oil.
Add mustard seeds, whole red chillies and curry leaves and allow it to splutter.
Add onion, green chillies, ginger, black gram and saute for 2 - 3 mins.
Add grated coconut and saute for a while.
Add 4 cups of water and the required salt and leave it to boil.
Add rava to the boiling water little by little, stirring continuously making sure that no lumps are formed.
Cook for another 3 - 4 mins in simmer.
Serve hot.