Fragrant aged basmati rice layered with spiced meat, saffron-infused milk, and sweet caramelised onions, sealed and slow-cooked in dum style.
Rub the raw mutton with yogurt, ginger-garlic paste, garam masala, green chilies, half the birista, and salt; rest 3-4 hours.
Boil the soaked rice in heavily salted water until three-quarters done; drain.
Spread the raw marinated mutton across the base of a heavy pot; blanket it with the drained rice.
Pour the saffron milk and melted ghee over, scatter the remaining birista, seal the lid with dough, and cook on high 5 minutes then low 45 minutes.
Rest 10 minutes without opening; fork through gently and serve.