Fry the sliced onions in oil till golden and crisp. Keep aside.
In the same pan, add spices and sauté till they begin to sizzle
Add ginger garlic paste and fry till the raw smell goes off.
Add parboiled potatoes and fry for about 3 to 5 minutes, till they are almost cooked.
Add the rest of the vegetables and fry for 2 to 3 minutes.
Add turmeric, biryani masala powder and red chili powder. Mix and fry well for 2 minutes till you get an aroma.
Pour 100 ml yogurt and mix.
Cook till the vegetables are done to tender.
Add mint and coriander leaves and set this cooked mix aside.
Cook rice till al dente in lot of water along with salt and shahi jeera. Drain off excess water.
Set aside ⅓ of the cooked vegetable and mix the rest of the cooked veggies, yogurt, nuts, raisins and fried onions and add it to a dum utensil or any heavy bottom utensil.
Layer the rice over the mix and layer the ⅓ cooked vegetable mix that was set aside. Sprinkle some fried onions
Layer rice over it again, then the fried onions, nuts, mint and coriander leaves and pour off the saffron milk and place a moist clean cloth to seal the rim. You can even use a foil or atta to seal the utensil.
Place the dum utensil on a hot tawa and cook for 5 minutes on a medium flame and then on low for 5 to 7 minutes based on the thickness of your utensil.