To start making the Kala Chana Masala, first wash and soak the black chickpeas for 5 hours or overnight in 2 cups of water.
Transfer chickpeas to Pressure Cooker with 2 cups of water and cook till 5 whistles, turn the heat to low and cook for another 20 minutes until done.
Heat oil in a kadai/pan over medium heat, add mustard seeds and cumin seeds, when it sputters add onion and a minute later add curry leaves. Cook the onions till golden brown then add ginger-garlic paste and green chilli paste, saute for few seconds.
Add in the tomatos and cook for 2 mins, then add coriander powder, cumin powder and mix well, also add small amount of chopped coriander and saute it. Now add turmeric powder, chilli powder, salt and mix well. A min later add the cooked chickpeas.
Stir to combine. Cover with the lid and cook for 5 mins over medium heat.
Turn the heat to low and stir the mixture. Now simmer the mixture for 3 more minutes. Adjust the taste of the dish according to your taste.
Now add the goda masala or garam masala, lemon juice and mix it well. Turn off the heat. Garnish with chopped coriander leaves. And Serve hot.
You can make gravy to it by adding water and simmering for more time, as per choice.