Clean and mince the mushrooms. Chop onion and tomato finely.
Place all the ingredients mentioned in the “to be ground” and without adding water, grind to a coarse paste.
Heat a pan with oil. Add mustard seeds and let it splutter.
Add onion and saute for 2-3 mins till it becomes translucent.
Add tomato, ground paste, turmeric powder, salt and mix well.
Cook for another 2-3 mins till the tomato becomes mushy.
Add minced mushrooms, sprinkle 1/4 cup water, mix well and let it cook over medium flame for 3-4 mins.
When they are about 3/4th cooked, add torn fresh curry leaves.
Cover the pan and cook for 2 more mins over medium flame.
This south indian mushroom curry should be semi dry in consistency before taking off fire.
Serve hot with Phulkas or pillowy Aappam.