Heat mustard oil in a pan on medium heat for about 5 minutes. Add chopped garlic and sauté it for 2 minutes. Then add the onions and fry them until they start becoming brown in color.

Now add ginger, green chillis and tomatoes to the pan and let it fry for about 5-7 minutes till the tomatoes become very soft and watery. Till this time, the raw mustard oil smell should also be eliminated.

Now add the chicken and mix well with the masala. Add the red chilli powder, black salt and black pepper powder and mix well. Let it cook for about 5 minutes.

Add a little water (or more if you want more curry) and mix well. Cover the pan and let cook for 20 minutes. Remove the cover and add the crushed curry leaves. Mix well and let it cook in the open pan for another 5 minutes.

Turn off the heat and enjoy hot and spicy chicken with plain/jeera rice or roti/paratha/naan.