Rinse the rice, lentils, and split peas thoroughly, then soak them in water for 25–30 minutes.
While soaking, prepare the other ingredients: dice the onion, crush the garlic, dice the tomatoes, grate the ginger.
Heat a pot over medium heat and add 2 tablespoons of ghee.
Add the mustard seeds and cumin seeds, toasting them until fragrant.
Stir in the red onion, ginger, garlic, green chillies, a pinch of salt, and curry leaves. Sauté for 2–3 minutes.
Add the diced tomatoes, then drain the soaked rice and lentils and add them to the pot.
Stir in the chilli powder, turmeric, and garam masala, mixing well.
Pour in fresh water until it covers the ingredients by 4–5 cm (1.5–2 inches).
Secure the lid and cook on high pressure for 12 minutes.
Once it starts whistling, lower the heat to maintain a gentle whistle.
Simmer on medium-low heat for 45–50 minutes, stirring every 5–10 minutes, until the rice and lentils have fully broken down.
To serve, ladle the khichdi into bowls, drizzle with the remaining tablespoon of ghee, and garnish with fresh coriander. Serve with a poppadom on the side.