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

Drain the soaked lentils and transfer them to a blender. Add 1/4 cup water and blend into a smooth batter. The consistency should be slightly thick but pourable.

Pour the batter into a mixing bowl. Add chopped onion, tomatoes, cilantro, grated ginger, green chili (if using), cumin seeds, turmeric powder, red chili powder, and salt. Mix well to combine.

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

Pour a ladleful of batter onto the pan and spread it gently into a thin circular shape, like a pancake.

Cook the chilla for 2-3 minutes on one side, or until the edges start to lift and the bottom turns golden brown.

Flip the chilla carefully and cook the other side for another 2-3 minutes until fully cooked and golden brown.

Repeat the process with the remaining batter, greasing the pan lightly between each chilla.

Serve the Masoor Dal Chilla hot with chutney, yogurt, or ketchup as desired.