Take a stockpot sized pot and put it on medium high heat, wait a few minutes, and then add the oil. When the oil is hot then add in the onions and the cumin seeds & cook until the onions start to turn golden brown at the edges. Highly recommend adding one of your green chilies (diced) in at this point.
Add the garlic and ginger pastes and saute for 30 seconds, then add the tomatoes salt, chilli powder, turmeric powder, and coriander powder. Cover and keep it on medium high heat and then uncover, the tomatoes should have broken down and become jammy.
Stir your chicken pieces in and saute until the colour changes.
Now in goes a cup of hot water, the chickpeas, and a pinch of baking soda (for touch chickpeas), bring it to a boil, and then let it cook covered on low heat for another 25-30 minutes.
When the chicken is tender then adjust consistency of your gravy by adding water then add the garam masala, the black pepper, the green chillies and cilantro. Cook for 2 minutes then taste and adjust seasoning.
Video
Notes
Chicken breast tends to overcook quickly, the best way to ensure a super tender chicken is to simmer for longer (35 minutes) than with bone in chicken pieces. For a longer simmer omit the baking soda.