Preheat oven to 275°F. Heat the ghee in a large heavy-bottomed pot over medium-high heat and add the onions. Cook, stirring often, until onions turn caramel brown – about 20 minutes. Add the ginger and cook an additional 2 minutes. Add cumin mace, cinnamon, garam masala, cayenne, and paprika; stir to distribute the spices, and cook for 1 minute.

Dry the lamb chunks thoroughly with paper towels. Increase heat to high and add lamb to the pot. Brown on all sides, turning and tossing them quickly, for about 5 minutes. Add half the yoghurt, half of the cream, and the salt; bring to a boil.

Remove from the heat, cover, and place in the pre-heated oven to braise for 2 hours. Stir the meat occasionally while it is in the oven to keep the sauce from burning. If the sauce completely evaporates, add a little milk. Remove the pot from the oven, and stir in remaining yoghurt and cream.