Soak black chickpeas overnight or for around 7-8 hours.
Pressure cook with enough water for 4-5 whistles or until they turn soft.
Drain the water and keep the chickpeas aside.
Heat 1 tsp oil in a pan.
Add green chillies all spieces except lemon juice and chaat masala to it.saute for 2mins.
Transfer to bowl add all chooped veggies mashed potatoes,coriander mix it well.
Add lemon juice and chaat masala and mix well.