Heat up the oil in a karahi dish (aka wok), cast iron skillet or any pan suitable for stir frying, keeping the flame on high for the entire duration.
Add the chicken into your preferred dish. Fry it by stirring constantly until the chicken begins to take on a golden colour in some of the places.
Add in the minced ginger and garlic. Fry this in the chicken completely, again stirring constantly and ensuring that nothing burns. Continue to fry this until the raw smell of the ginger and garlic begins to fade away.
Add all the chopped tomatoes and Handi spices. Stir it in and allow it all to cook on high flame, stirring constantly to ensure nothing sticks at the bottom of the pan.
Continue to cook this mix for about 20 minutes. The oil will separate, the tomatoes will thicken and begin to coat the chicken, and you will see holes beginning to bubble in the gravy. The chicken should be cooked thoroughly at this point.
Add the coriander and green chillis and stir it in. Turn the heat down to a low flame and allow everything to simmer together for 5 minutes without putting the lid on.
Serve by garnishing with the matchstick-cut ginger and add coriander/green chilli if desired.