Firstly rinse chickpeas with water for a couple of minutes now soak chickpeas overnight or for 7-8 hours in enough water. Afterwards drain excess water from the chickpeas and keep it aside.
Meanwhile take a pressure cooker add oil and heat it on high flame.. When oil starts to smoke add finely sliced onions and green chiles.. Since the oil is hot enough the onions and chillies will be translucent with fraction of minutes.. Saute it
Now add tomatoes and saute till mushy.. Now add soaked chickpeas and all the other spices.. Stir it.. Add water and close the lid of the pressure cooker... And upto 5-6 pressures or for about 15-20 min On medium flame and afterwards put of the flame.
Once the pressure settle down on it's own remove the lid of the cooker and check whether chickpeas are tendered enough... Cooking of chickpeas varies about the quality of the chickpeas.. Continue cooking again for few more minutes with the lid closed if chana is not completely tendered. Put of the flame
Once the pressure settle down on it's own remove the lid and shimmer the chana masala gravy on slow to medium flame till the gravy thickens slightly. Mash some chana pieces with spoon as this helps in thickening of the gravy... Chana masala gravy should be of medium consistency.. Put off the flame.
Garnish chana masala with onion rings, lemon wedges and fresh coriander leaves and green chilli.
