Marinate the mutton with yogurt, ginger paste, garlic paste, 2 tbsp Kashmiri red chili powder and a bit of salt. Keep it for at least 3- 4 hours. Overnight is preferable.
Cut the onions into thin slices. In a wok or a kadai, take 2 tbsp of mustard oil and when it is hot add 2 dried red chilies and half of the onions. Fry until deep golden brown in colour. Then take the fried onions and the red chili and make a paste in the grinder. You will not need any water but add a little bit if required. Keep the paste aside for later use.
In the same pan, add the rest of the mustard oil. When it is super hot, reduce the flame and add bay leaf (crushed with your hand), whole cinnamon, whole green cardamoms, whole cloves, more dried red chilies if you want, a tea spoon full of sugar and half a tea spoon of salt.
When the whole spices start to splutter, add the sliced onions. Fry on medium heat till it is golden brown. While frying this, add a couple of heaped teaspoons of Kashmiri red chilli powder (or more) and one teaspoon of normal red chilli powder. Kashmiri red chili powder does not have any heat and it only imparts colour and flavour.
When the onions are almost fried, add the fried onion paste and continue stirring for a few more minutes till all the raw smell has gone off.
Then add the marinated mutton.
Mix it all very well in the wok and keep stirring and cooking till the mutton has browned. At this point, to reduce the amount of effort, just transfer the entire content to a pressure cooker. You may do it completely in the kadai as well.
Use a cup of water to clean the wok and put it in the pressure cooker.
Pressure cook this for a few minutes (3 -4 whistles). This will only cook the mutton by half.
Now take it out and put it all back in the wok. Here starts the hard work (or as we call it...koshano).
Continue cooking and stirring till the water evaporates. This process takes a lot of time since you have to ensure that the mutton cooks. For that, you need to cover it with a lid and slow cook it. You will notice the colour changing and becoming darker eventually.
From time to time, uncover, increase the heat and stir while making sure nothing is sticking to the bottom of the wok.
It completely depends on how much time you want to devote to getting the right colour and depth of flavour. This particular time, I took almost 2 and a half hours to finish. Sometimes, , it takes 3 hours. It depends on the age of the mutton.
When the mutton is almost cooked, add ground garam masala. Adjust the seasoning.
Serve it with some steamed rice or parathas or luchi.