To cook the Chicken:
Heat 6 tbsp oil in a heavy bottom pan and add the sliced onions.
Fry on high heat for around 12 mins till the onions are light brown.
Add the ginger garlic paste and fry on low heat for 2 mins.
Now add the chicken pieces, mix and fry on high heat for 2-3 mins.
Add the ready made Biryani Masala, mix and fry on medium heat for 3 mins after adding a splash of water.
Readymade Biryani Masala usually contains salt, hence salt is not added while cooking the chicken in this recipe. Do check if the biryani masala you are using has salt in it.
Now add the sliced tomatoes, mix it well and cook on medium to low heat for 4-5 mins till soft.
Keep the heat on low and add the whisked curd/yogurt. Give a mix and then add the chopped coriander and mint leaves.
Cook on low heat for 2 mins till oil separates.
Cover & cook on low heat for around 20-25 mins till chicken is tender. Remove lid after 10 mins, give a mix and close the lid again.
Dry up any excess water to get a thick gravy.