Boil 1 kilo mutton in a pressure cooker for 20 minutes on a medium heat. Remove the scum and add 1 tsp of garlic paste, 4 pieces of cloves, 1 piece of whole black cardamom, 4 pieces green cardamom (whole pods), a 2-inch stick of cinnamon, salt to taste, 1 tsp of fennel powder and ½ tsp of ginger powder (sonth). Cover and cook for another 20 minutes. (Pro tip: Don't skip skimming the scum thoroughly at this stage. It is the difference between a pale, clean-tasting yakhni and a murky one. A slotted spoon clears it faster than a ladle).
Heat 1 cup Dahi on a medium flame in a kadai and crack one egg in it. Before it comes to a boil, add a 2-inch cinnamon stick, 1 tsp of garlic paste, 4 pieces of cloves, 4 pieces of green cardamom (whole pods), 1 piece of whole black cardamom, salt to taste, 1 tsp of fennel powder, ½ tsp of ginger powder and ½ tsp of meat masala powder. Mix and cook until it reduces.
Fry a medium-sized, finely sliced onions in 4 tbsp of mustard oil on a medium flame. (Pro tip: Remove the moment they turn amber, not deep brown — they keep darkening in residual heat and turn bitter if fried too far).
Transfer to a blender, add 4 pieces of cashew nuts, and make a paste.
Add it to the Dahi mix along with 2 tsp ghee. (Pro tip: Replace ghee with a bit of the oil left after frying onions if it is unavailable).
Check the mutton. When the Dahi mixture comes to a boil, add the boiled mutton along with the stock. Cook for another 15 minutes.
Add a handful of crushed dry mint leaves. Mix, cover the kadai with the lid until the stock reduces. Check the doneness and transfer it to a serving bowl.
Your tasty and spicy homemade Kashmiri yakhni soup is ready.