Heat the oil in a large pan.  add mustard cumin Add the onions,  turmeric ginger garlic paste curry leaves,  and green chilli and saute for a while add tomatoes . . Then, add the coriander, cumin pdr  or  garam masala ( optional) and salt and mix well. Add the chicken to the frying pan and mix well,  and cover and cook over a low-medium heat for 10-15 minutes or until the chicken is cooked through. When the chicken is almost done, add the ground pepper into the mixture and mix well.