Firstly, take a cooking vessel, add oil and heat it.
Into it add cumin seeds, mustard seeds and let it splutter.
Add chopped onions, slit green chillies, curry leaves and saute for few minutes until onions get soft.
Add ginger garlic paste and saute well to get rid of raw smell.
Add the blended tomato puree, stir and cook for few minutes on low flame until oil starts separating.
Add the spices such as salt, red chilli powder, turmeric powder, coriander seeds powder, cumin seeds powder, black pepper powder and mix well.
Cook the whole mixture until the masala is cooked well or until oil starts leaving the sides.
Add roasted coconut paste(preferred)/ coconut milk and mix well.
Cook the masala until oil is seen at the sides.
Add coriander leaves and mix.
Add little water as per the thickness of the gravy preferred.
Cover the lid and cook on low flame for ten to fifteen minutes.