Marinate the ground lamb with 1/2 tsp of red chili powder, 1/2 tsp of turmeric powder and 1 tsp of salt for 2 hrs. Add the green chili, half of the ginger, 1 clove of crushed garlic, half of the chopped onion and the egg yolk to the marinated lamb. Form this meat mixture into small lemon sized balls and set aside.
Soak the tamarind in 1 1/2 cups of hot water for 5 minutes and strain. Reserve the tamarind juice to one side. Make a paste with the remaining red chili powder, turmeric powder, coriander powder, tomato paste and a tablespoon of tamarind juice. Beat the egg white and set aside.
Heat 1 tablespoon of oil in a large heavy pan and fry the cinnamon, cardamom pods and cloves for a minute. Add the spice paste and fry until the smell of the spices comes out. Add the remaining onion, ginger and garlic and cook until the onion is soft. Then add the tamarind juice, tomato, cumin powder and salt. Bring this to a boil. Add the cubed potato and carrot. Cover the pan and cook for 10 minutes. Then dip the meatballs in egg white and lower them into the boiling gravy. Cover and cook for 15-20 minutes. Garnish with chopped coriander leaves and serve hot.