Drain the soaked lentils and transfer them to a blender with 1/2 cup water. Blend until smooth.
Pour the batter into a mixing bowl and stir in onion, chili, cilantro, cumin seeds, and salt.
Heat a non-stick pan over medium heat and lightly oil the surface.
Scoop about 1/4 cup batter onto the pan and spread gently into a circle.
Cook for 2 to 3 minutes until bubbles form and the bottom is golden, then flip and cook the other side.
Repeat with the remaining batter, oiling the pan lightly as needed.
Serve hot with yogurt, chutney, or your favorite breakfast sides.