Rinse the red lentils thoroughly under running water and soak them in water for 2-3 hours or until softened.

Drain the soaked lentils and transfer them to a blender. Add 1/4 cup of water and blend into a smooth batter. Add more water if needed, but ensure the batter remains thick and pourable.

Transfer the lentil batter to a mixing bowl. Stir in the chopped onion, tomato, green chili (if using), cilantro, turmeric, cumin, chili powder or paprika, and salt. Mix well to combine all the ingredients evenly.

Heat a non-stick skillet or griddle over medium heat and lightly grease it with cooking oil.

Pour a ladleful of batter onto the skillet and spread it gently into a thin pancake using the back of the ladle.

Cook the chilla for 2-3 minutes on one side or until golden brown and slightly crispy. Flip it carefully using a spatula and cook the other side for another 2-3 minutes.

Repeat the process with the remaining batter, greasing the skillet as needed.

Serve the Masoor Dal Chillas hot with chutney, yogurt, or your favorite dipping sauce.