In a mixing bowl add wheat flour, rice flour, and semolina. Stir in yogurt, onion, coriander leaves, green chili, cumin seeds, salt and half a cup of water.
Mix well and add more water to make a smooth batter like dosa batter.
Heat a skillet and season it with oil. Spread a ladleful of batter on the tawa in a circular, motion to make a dosa.
Smear some oil on sides and cook for 2 minutes. Repeat the same with rest of the batter.
Remove from heat and serve warm with coconut chutney.
Notes
You may also make the dosa with a thin batter like rava dosa and sprinkle it on hot tawa.