In a bowl combine lamb, ginger-garlic paste, yogurt, coriander powder, cumin powder, red chili powder, turmeric powder, and salt.
Mix well and let it marinate for at least 30 minutes.
Add a pinch of baking soda to the marinated lamb. This would help to tenderize the meat and reduce cooking time.
Heat oil or ghee in a karahi or any pan which have a heavy bottom on medium-high heat.
Add the sliced onions and fry until they turn golden brown.
Add a pinch of sugar to the onions while frying for faster caramelization and a richer color.
Add the marinated lamb and cook it until browned on all sides.
Reduce heat to medium, add the chopped tomatoes and green chilies. Cook until the tomatoes become soft and release their juices. They would form a thick gravy.
If you are using canned tomatoes, add a teaspoon of sugar to balance the acidity.
Add chopped ginger and garam masala powder also called warming spices. They are a mixture of many spices and you can get them from the store in a pack.
Mix well chopped ginger and warming spices and simmer for about 15-20 minutes, or until the lamb is tender and cooked through.
Garnish with chopped coriander leaves and serve hot with naan, roti, or rice.