First, clean and wash the meat, then pressure cook or boil it with 4-5 cups of water, 1 tsp each of ginger and garlic pastes, 1 tsp salt, 1 tsp black pepper, 1 grated tomato and 1 grated onion. If you're using a pressure cooker, mutton/lamb should be ready in about 25 mins. If boiling in an open pan, it might take a little over an hour...so you will have to keep adding enough water to keep the meat completely immersed in the water at all times. Beef generally takes longer to cook than mutton/lamb.
Once the meat is ready and tender, drain it and set aside. Reserve the soup for cooking the rice. For every cup of rice, you will need 1 and a quarter cup of liquid. So check how many cups of rice you have, and adjust the liquid accordingly. If there is too much soup, reduce some. If there is too little, compensate by adding water.
Heat a pan on the stove and heat the oil and butter. Remember that the rice will double after cooking, plus the meat and potatoes that will go in there, you will need to have enough space in the pan.
Then add the whole spices. Cumin, cardamom, cinnamon, pepper, cloves.
Once they splutter in the oil, add your chopped onions. Fry them until they are translucent, stirring with a wooden spoon. If you want a darker pilau, fry the onions until they are dark and caramelised. Then add the potatoes followed by the turmeric and cumin/coriander powder.
Let these fry for a few minutes, then add the garlic paste and a bit of chopped coriander.
The aroma should by now be brilliant. Add in the boiled meat now. Stir together for a few minutes, then add the stock/soup and some salt. Let the stock simmer and taste for the salt. You should be able to feel the saltiness. If it feels just right, it means you have too little. Remember that the rice will need some salt too, so let the salt be enough that you can taste it to be a bit more than you would want. Not too much of course!
When the water starts boiling, drain your rice (which should have been pre-soaked for about half an hour) and add this rice to the stock. Sprinkle a bit of coriander on this, and stir a little. Let this cook on high heat for 2-3 minutes then reduce the heat to medium and keep cooking it whilst covered until the water diminishes, giving it a stir every now and then to make sure all the rice is cooked evenly and perfectly.
Once you find there is very little water left in the rice, reduce the heat to the lowest point possible. Seal your pan by using a tight lid or wetting a kitchen towel and placing it over the pan then placing a lid on top of it.
Leave the rice to continue steaming on very low heat for a good 10 mins. Switch off, and serve!