Wash and soak the yellow lentils, then roughly chop the onion, tomato, garlic, ginger, and green chili so they are ready to go into the pot.

Add the soaked lentils, chopped onion, tomato, garlic, ginger, green chili, turmeric, and water to a pressure cooker and stir to combine.

Pressure cook the mixture until the lentils turn completely soft and mushy, breaking down easily when pressed between two fingers.

Let the mixture cool slightly, then blend it to a smooth, uniform consistency using an immersion blender or a countertop blender.

Return the blended soup to the pot, stir in the cumin powder, black pepper, and salt, and simmer gently until the soup thickens slightly and the raw spice smell disappears.

Heat the ghee in a small tadka pan, add the cumin seeds and dried red chilies, and let them sizzle until the cumin turns fragrant and slightly darker.

Pour the sizzling tadka over the soup, stir in the lemon juice off the heat, and taste to adjust the salt or lemon before serving.

Let the soup rest for a couple of minutes so the tadka infuses through, then ladle into bowls and garnish with chopped coriander leaves.