Heat 4 tablespoon of ghee in a pan fry the sliced onion in batches to golden brown and remove with a slotted spoon.
Drain on absorbent paper. In the same pan salute half the black cumin seeds till they begin to sizzle. Add 2 cloves 1 cinnamon stick half the mace the nutmeg and peppercorns and saute till fragrant.
Add the ginger and garlic paste and saute for 1 min. Add salt pepper and the vegetables and saute over a low heat for 1-2 minutes.
Add yoghurt and cook till the vegetables are almost tender.
Meanwhile in a separate large pan bring 8 cups water to a boil with 2 tablespoon of salt or to taste. Tie the remaining cloves, cinnamon tick, mace, black cumin seed, black cardamom, green cardamom, in a piece of muslin cloth to make a small bundle.
Add to the water with bay leaves. Cook on a low heat for 15-20 mins to allow the spices to infuse the water with their flavour.
Drain the the rice and add to the pan and cook till half done. Remove from the heat and strain. Reserve the strained water.
Stir the remaining ghee into the rice and set aside.
To assemble the biryani spread half the fried onions at the base of a deep heavey bottomed heatproof casserole.
Spread half the rice over the onions.
Spread a layer of the vegetables and the chopped mint over the rice . Cover with the remaining rice and top with fried onions.
Sprinkle the rose water and the kewabs water.
Cover with a lid and seal it with the dough. Place on a hot area or griddle and cook on a low flame till steam begins to escape.
Remove from heat a d let stand for 2 mins. Remove the dough seal uncover and fluff up the rice with a fork.