Heat oil in a pan and add mustard seeds once oil is hot. Allow to splutter then add chopped onions, cook till golden brown. Then add the ginger garlic paste and cook till raw smell disappears. Add the red chilies and sauté for a few minutes till raw smell disappears.

Then add the chopped tomatoes and fry till the oil separates. Then add the 3 tbsps water and the turmeric powder, chill powder, coriander and cumin powder. Roast for 7 minutes or until the raw smell disappears.

Meanwhile in another pan  melt the butter and add the chopped mushrooms and salt. Roast until it has a slight golden brown. Add these roasted mushrooms to the masala mix, then add the yoghurt and coconut milk.

Mix well and cook with lid on on low heat for 5 minutes. Be careful no to over cook the coconut milk and yoghurt as it can curdle.

Garnish with coriander leaves and spring onion leaves. Check salt. Cook for 2 minutes on low heat. Serve hot with rice or chappathi.