Soak the chana dal for an hour. Wash and drain.
Cook in sufficient water along with the turmeric and salt till almost done. When pressed, it will smash but will still have a bite in between. Drain and set aside.
Cook the rice in lots of water and some salt till 90% done. Drain and set aside.
In a large saucepan, heat ghee. Fry 1/4 of the onions till browned. Drain and set aside for dum.
Into the same ghee, add the remaining onion and saute till wilted.
Add the ginger garlic paste and saute for a minute.
Now add the yogurt and fold in well. Add in the powders and cook for a few minutes.
Add the drained dal and cook for a couple of minutes. Add salt and switch off.
Keep the dum ready. Sprinkle half of the fried onions, coriander leaves, mint leaves and chillies on top of the dal gravy.
Spread the rice over it. Sprinkle the remaining dum ingredients and drizzle the saffron milk over.
Cover tightly with foil, close the lid and keep on dum for 20 minutes. Once switched off, leave the biriyani till serving time.
While serving, fluff up with a ladle and serve hot with raita, pickle and pappad.