Combine and grind the vallarai keerai, green chillies, cumin seeds and salt.
Add this to the dosa batter and mix well.
Keep aside for 10 to 15 minutes.
Heat a flat tawa over medium flame.
Pour a ladleful of the batter and spread evenly.
Apply little oil around the edges.
Cook on both sides and remove from flame.
Serve with a choice of chutney and sambar.