Marinate the mutton with yoghurt, ginger-garlic paste, 1 tbsp of the Tehari Spice Powder and 1 tbsp mustard oil, refrigerate for at least 2-3 hours, even better if it can be left to rest overnight.
Heat 3 tbsp oil in a pan, throw in the sliced onions, fry till light brown.
Add the mutton along with the marinade, throw in 4-5 green chilies, sprinkle in the salt and ½ tbsp of the Tehari Spice powder, continue to cook over a low heat till oil starts to release from the masala.
Add 1/2 a cup of warm water, bring to a gentle simmer.
Transfer to a pressure cooker. Cook over a medium flame, 3 whistles I would reckon. Allow the steam to release on its own.
Separate the mutton pieces from the gravy, keep aside in two separate bowls.
Heat the remaining mustard oil in a deep bottomed pan, throw in the bay leaves, crushed green cardamom and cinnamon, allow the spices to splutter.
Gently stir in the mutton gravy, cook over a low flame till it reduces to just a coating consistency.
Now add the rice, give a gentle stir, taking care not to break the grains.
Add 4 cups of warm water (golden rule - rice and water should always be in a 1:2 ratio), sprinkle in 1 tbsp of Tehari Spice powder and salt to taste.
Cover and cook till almost half of the water has been absorbed.
Gently place the mutton pieces on the rice, throw in half the fried onions and the remaining green chilies, sprinkle in ½ a tbsp of the Tehari Spice powder.
Cover and cook till almost all the water has been absorbed, by which time the rice should be done.
Switch off the flame, add the remaining fried onions, cover and allow to rest for a further 10-12 minutes. Mix gently, serve hot.