1. Marinate the lamb with yogurt, ginger garlic paste, biryani masala, turmeric, and salt. Let it sit for at least 30 minutes.
2. Heat ghee in a large pot. Fry the onions until golden brown. Remove half of the onions and set aside for garnishing.
3. Add the marinated lamb to the pot and cook until the lamb is browned and cooked through.
4. In a separate pot, boil water and cook the soaked rice until it is 70% cooked. Drain and set aside.
5. Layer the partially cooked rice over the lamb in the pot. Sprinkle the reserved fried onions, coriander, and mint leaves on top.
6. Cover the pot with a tight-fitting lid and cook on low heat for 20-25 minutes until the rice is fully cooked and the flavors have melded together.
7. Serve hot, garnished with additional coriander and mint leaves if desired.