Preheat a ghee in a large heavy-bottomed pot. Brown the meat in batches. Don't overcrowd the pot or you'll end up steaming the meat instead of browning. Set aside in a bowl
Add onion into the same pot and stir-fry until fragrant, scrapping the bits at the bottom of the pot at the same time. Add in the spice paste, cayenne, paprika, curry powder,and bay leaf to pot and continue to stir fry until fragrant
Tip the lamb back into the pot along with its juices. and simmer for about 3-4 minutes. Stir in the yogurt into the pot. Add the cinnamon stick and add in 2 cups of hot water, and pepper to taste
Cover the lid partially and cook for 1 hour or so or until the lamb is really tender. When the meat is tender already, stir in the garam masalaand let it simmer for another 5 minutes. Remove the cinnamon stick and bay leaves before serving. Serve with warm rice or naan