Rinse 1 cup moong dal and soak it in water for 3 to 4 hours
Drain the water and blend the soaked dal with 1 to 2 green chilies, 1 small piece ginger, and little water to make a smooth batter
Transfer the batter to a bowl
Add salt, 1/4 teaspoon turmeric, chopped coriander leaves, and finely chopped onion if desired
Mix well and adjust the consistency with a little water if needed
Heat a non-stick pan or tawa on medium heat
Grease it lightly with oil
Pour a ladleful of batter onto the pan and spread it into a thin circle
Drizzle a little oil around the edges
Cook until the bottom turns golden
Flip and cook the other side until lightly browned
Remove from the pan and repeat with the remaining batter
Serve hot with chutney or curd