1. Lamb Leg: Heat up cooking oil in a pan. Sauté sliced onion, garlic and ginger until fragrant. Add in cinnamon, cloves, cardamom pods and star anise and stir for a few minutes.
2. Once the onion has turn light golden brown, add in cumin and coriander powder. Stir until the oil has floated on the surface, for 3 minutes. Season with salt and sugar and leave the paste aside to cool.
3. Place lamb leg in a baking tray and rub the cooled paste all over it. Over with cling wrap and let it marinade in the fridge overnight.
4. Let the lamb leg comes to room temperature before roasting it. Preheat oven at 130°C and cover lamb leg with aluminum foil loosely. Roast the lamb leg, covered for 2 hours, and uncovered for another hour. Once done, remove from oven and set aside.
5. Biryani Date Rice: Melt ghee in a pot. Sauté sliced onion, garlic and ginger until fragrant.
6. Add in cinnamon stick, cloves, cardamom pods and star anise and stir for another minute.
7. Add coriander powder and salt into the pot and continue stirring, until the paste has release the oil.
8. Transfer the paste into rice cooker pot and add in washed basmati rice. Pour in water and evaporated milk. Cook the rice following to the rice cooker instructions.
9. Once cooked, transfer the rice into big bowl and leave to cool slightly. Toss it with coriander and mint leaves, chopped dates, fried onion and cashew nuts.
10. Kurma Gravy: Heat up oil in a pot and sauté sliced onion, garlic and ginger for a few minutes. Add in cinnamon stick, cardamom pods, star anise and cloves and sauté for a minute.
11. Add in biryani and coriander powder. Once the oil has floated in the surface, stir in water and evaporated milk. Let it boil for a few minutes untl it thickens ups and season with salt accordingly.