Soak black chickpeas for 8 hours.

Pressure cook the soaked black chickpeas with water and salt until tender (3-4 whistles, then simmer for 15 minutes).

Let the pressure release naturally.

Mix tamarind paste with water in a bowl and set aside.

Heat oil in a pan or kadhai.

Sauté sliced onion, minced garlic, and chopped green chilies until the onion is soft.

Add curry leaves, tamarind mixture, tomato puree, jaggery, salt, and coconut milk.

Cook for 1 minute.

Add red chili powder, coriander powder, and garam masala powder.

Simmer on low heat for 10-12 minutes, allowing the flavors to meld.

Serve hot with lachha paratha, cabbage and carrot thoran, or rice.