This spicy biryani has got to be one of the most flavourful biryani versions and is extremely popular all over the world. It originates from the Sindh province of Pakistan. What makes any biryani intensely delicious is partly due to the amount and variety of spices used and partly from the love and care that goes into the cooking process. So here's a tip, be joyful as you cook this meal and the results will thank you for it! ;)
Marinate the meat in the remaining marinade ingredients for at least 2 hours or preferably refrigerate overnight. This helps tenderise the meat and builds flavour. Remember to remove the meat half an hour before you begin cooking to bring it to room temperature.
Deep fry the potato chunks on low heat until a knife pierced through the centre of each potato piece yields easily. Drain and set aside (you may opt to boil the potatoes if you like, but I find they hold their shape and taste a lot better fried).
Wash and then soak the rice for about 20-30 minutes.
Heat the half cup of oil in a deep pan and then fry the onion slices until golden. Remove a quarter of the fried onions (these will be used later) and leave the rest in the pan. Add the whole spices (cumin, cadamom, pepper, cloves, bay leaves, cinnamon and black pepper). Once they sizzle, add the garlic and ginger pastes and stir them in until aromatic. Next, add tomatoes, prunes, turmeric, salt and red chilli powder.
Stir and cook this down until the tomatoes are completely mushy and all the excess moisture is gone. You will notice that the oil begins to get released from the sides. Add the green chillies and the meat with it's marinade. Allow the meat to cook in the tomato mixture for a few minutes, then add the whipped yoghurt plus the saffron mixture and mix well. Then add about a cup of water (use just half cup water if cooking with chicken as it will cook faster than meat) and cook until the meat is tender and the masala/gravy is nice and thick. I normally do this in a pressure cooker when working with mutton/goat, takes less time. But you can do it in a regular pan, just keep adjusting the water until the meat is fully cooked. Now add the fried potatoes and stir them in. Sprinkle the garam masala, then cover and set this aside while you prepare the rice.
Bring a large pot of water to the boil, add about 2 tbsp salt to it and 2 tbsp oil plus a few whole spices (two pieces each of cardamom, cinnamon sticks, cloves). Then drain the soaked rice and add it in. Cook until the rice is al-dente, do not cook it all the way. It should be about three quarters of the way cooked. This should take about 8 minutes or less. Drain the water off.
Layer the meat masala with the rice, remembering to sprinkle the reserved fried onions, chopped coriander and mint and some food colouring over the rice in between the layers. Cover with a tight lid and place on very low heat for about 15 minutes to steam. Once done, open and fluff up the biryani gently.