Add little oil to kadai and add urad dhal and fry till golden color.
Then add cut onions and fry till translucent.
Now add other ingredients.(green chillies,ginger piece,curry leaves and tomatoes with some salt)
Fry till raw smell goes off .
Finally add grated coconut and switch off the stove.
Let it cool.
Then grind it and serve with idli or dosa.
Notes
Grind the content after it cools.
Even red chillies can be added instead of green chillies.
The spice level varies according to individual preferences.