Firstly, soak the kala chana in enough water in a deep bowl overnight. Next day, drain it.
Add the chana and enough water in a pressure cooker and pressure cook for 4 whistles.
Allow the steam to escape before opening the lid. Drain and keep aside.
Heat the butter in a deep non-stick kadhai, add the green chilli paste and onions and sauté on a medium flame for 2 to 3 minutes or till the onions turn translucent.
Add the tomatoes, and other veggies, chilli powder, garam masala and chaat masala, mix well and sauté on a medium flame for another 2 to 3 minutes.
Add the chana, salt,coriander and lemon juice, mix well and cook on a medium flame for another 2 to3 minutes, while stirring occasionally.
Enjoy the healthy snack.