Add the yogurt, half of the garam masala and four bay leaves to the mutton in a bowl.
Mix it well, add salt and pepper powder.
Keep aside in fridge for at least 5 hours.
Soak rice in enough water for at least 1/2 an hour.
Slice the onions and peel the garlic cloves.
Heat oil in a pan and add half the onions and saute until they turn golden brown.
Remove and keep on a paper towel so that the extra oil is drained.
In the same oil, add the remaining whole spices, 2 bay leaves and cook for a few seconds on low heat.
When the spices start to change their colour, add the crushed garlic cloves.
Cook for a couple of seconds and add the remaining onions.
When the onion becomes translucent, add salt.
Remove the marinated chicken after lightly squeezing out the extra marinade and add the pieces to the pan.
Keep the yogurt marinade in reserve.
Cook the mutton pieces for at least 15-20 mins and then add the marinade to the mutton and cook for further 15 mins.
Transfer the mutton mixture to a pressure cooker and cook at full steam for about 10 - 12 mins. Then simmer for 15 mins.
Remove the pressure cooker from fire. Once all the steam subsides, transfer only the chicken pieces and sieve the residue with a wire strainer. Mash the contents through it and then discard the residue.
Add this liquid to the water needed for cooking rice (it should be 1 rice: 2 water).
Take a heavy bottom pan, grease its bottom and the sides.
Make a layer of bay leaves so that the surface of the pan is totally covered with the leaves.
Take the soaked rice, add a layer of rice to the pan and alternately put a layer of mutton and water. Repeat till the topmost layer is rice.
Add a little onions between the layers and the remaining on the top.
Make a dough with wheat.
Cover the lid of the vessel, seal the edges ot the lid with the dough and keep on high flame for 5-6 mins. Then cook on low fire for further 12-15 min.
Once the dough seal becomes hard and crusty, remove from fire and serve.
Also add a little saffron soaked in warm milk in the marinade.