Wash and soak 1 cup of split yellow moong dal in water for 3-4 hours.
Drain the water and grind the soaked moong dal with 1-2 green chilies, a small piece of ginger, and a little water to make a smooth batter. The consistency should be similar to dosa batter.
Add salt to taste, 1/2 teaspoon of cumin seeds, and finely chopped coriander leaves to the batter. Mix well.
Heat a non-stick tawa or griddle over medium heat. Pour a ladleful of batter onto the tawa and spread it evenly in a circular motion to form a thin chilla.
Drizzle 1 teaspoon of oil around the edges of the chilla and cook until the bottom turns golden brown. Flip the chilla and cook the other side until golden brown as well.
Serve the moong dal chilla hot with green chutney or yogurt.