Step 1: Soak rice for half an hourWash the rice under cold running water and soak it for half an hour.
Step 2: Fry the sliced onionHeat a pan with 4 tablespoons of ghee over moderate flame. Fry the sliced onions till golden brown and remove with a slotted spoon. Drain fried slices of onion on absorbent paper.
Step 3: Saute the whole spicesIn the same pan, saute half of the black cumin seeds till they begin to sizzle. Add cloves, cinnamon, half of the nutmeg, peppercorns and saute them till they get fragrant.
Step 4: Saute the vegetables with yoghurtAdd ginger and garlic paste and saute for one minute. Now add salt, pepper, butter, yoghurt and vegetables and saute them over low heat till the vegetables are almost tender.
Step 5: Boil water with saltMeanwhile, in a separate large pan, bring 8 cups of water to a boil with 2 teaspoons of salt.
Step 6: Make a bundle of whole spicesTie the remaining cloves, cinnamon stick, cumin seeds, black cardamoms and green cardamoms in a piece of muslin cloth to make a small bundle (potli) and add to the water with bay leaves. Cook on low heat for 15-20 minutes to allow the spices to infuse the water with their flavour.
Step 7: Cook rice in the above waterDrain the rice, add to the pan and cook till they are half done. Remove from the heat and reserve the strained water.
Step 8: Assemble the vegetable biryani and serve hotStir the remaining ghee into the rice and set aside. To assemble the biryani, spread half the fried onions at the base of a deep heavy-bottomed heatproof casserole. Spread half the rice over the onions. Then spread a layer of the vegetables and the chopped mint over the rice. For garnishing, sprinkle rose water over the rice. Serve hot with raita.
You can make it more aromatic by adding saffron strings and kewra water.
You can also add cashews over the biryani for a royal touch.