Heat oil in a pan.
Splutter black mustard seeds.
Add grated ginger and chopped garlic and saute for a minute.
Saute chopped onions, until lightly browned, for about 8 - 10 mins.
Add chopped tomato and cook until soft, for about 5 - 7 mins.
Mix in red chilly powder, coriander powder, cumin powder, asafoetida, turmeric powder, pepper powder, garam masala and salt.
Mix thorougly for about 1 - 2 mins.
Add chicken pieces and saute thoroughly over medium-high heat (adjust heat as needed).
Stir regularly so it doesn`t stick to bottom.
:- If it sticks add little more oil.
Cook chicken until well done.
:- Gravy should be dry. If boneless chicken, cook for about 20 - 25 mins. If boned chicken, cook for about 35 -40 mins.