Indian
Marinate the lamb in the yogurt with half the ginger and garlic for at least 30 minutes.
Heat the ghee in a heavy pot and fry the onions until browned, then add the remaining ginger and garlic and cook for 1 minute.
Stir in the ground coriander, cumin and chili powder, then add the tomatoes and cook until they break down into a thick masala.
Add the marinated lamb and stir well, searing for a few minutes until the meat is coated and lightly browned.
Pour in 300 ml water, season with salt, cover and simmer gently for 75 minutes until the lamb is fork-tender.
Sprinkle in the garam masala, simmer uncovered for 5 more minutes to thicken, and serve with basmati rice.