Wash and dry the mutton pieces. Mix all the marination ingredients together and pour over mutton. Using your hands, gently mix the mutton pieces & marination mix together. Make sure all the pieces of mutton are well coated with the marinade. Now, cover this, keep it in the fridge and forget all about it for the next 12 hours or at a bare minimum overnight. The longer the marination, the better the flavour in this case.
Now, put a thick-bottomed pan or a kadhai (I use my traditional sipri) over medium flame and add ghee in it. Once the ghee is melted, add coriander seeds and let them splutter for 15-20 seconds. Now it's time to add the marinated mutton along with the marinade. Stir to mix well all the ingredients and turn to high flame until the liquid comes to a boil.
Now reduce the flame to minimum, cover the mutton and go read a book or watch a Netflix show. While you are relaxing put a cyclic timer for 8-10 minutes and every time the timer goes off, go stir the mutton gently. Totally enjoy this for the next two hours, maybe even do some self-care with a face mask. Don't let anyone guilt-trip you, you are cooking them awesome dinner after all.
Once the mutton is cooked, the gravy releases ghee, turn off the gas. Garnish with coriander leaves. Unfortunately, it's time to leave the book aside for a while, cook up some paranthas on the side and enjoy the dinner. This pairs very well with single malt, I am not asking you to drink. I am just saying ;)