Discard the water used to soak chickpeas and rinse twice. In a pressure cooker, place the rinsed chickpeas, add water so that it stands above the chickpeas. Pressure cook for 4 to 5 whistles till they are cooked soft. Drain the water and let it cool.
When completely cool, mash using a potato masher and keep it aside
Heat a pan. Add oil and when warm, add onion and sauté till pink.
Add green chillies, mint, coriander leaves and sauté till they leaves shrink.
Add coriander powder, red chilli powder and sauté. The contents of the pan will dry up.
Add the ground paste and cook for 3-4 mins over medium flame, stirring in between till the raw smell disappears. If this mixture appears more dry then add 1-2 tbsp more oil.
Add boiled and mashed chick peas, salt and mix well and cook for 2 more mins.
Add mashed potatoes. Mix well and take off fire.
Add lemon juice, if using, mix well once again and keep aside to let it cool down completely.
Once cool, make even lemon sized balls and set aside.