Start by heating oil in a pot. Add a bay leaf and some black peppercorns into it and saute for a minute. Now add 1 large thinly sliced onion into it and let it saute until it softens.
Next, add the ginger garlic paste and the lamb chunks and saute for 5 minutes.
Now, add the Nihari masala, turmeric powder, red chilli powder and cook for 2-3 minutes.
Now add the water and turn down the heat and cover the pot with a lid. Let this simmer for around 2 hours until the meat is soft and tender.
Once the meat is cooked well, create a slurry using flour and a bit of water, and add it into the Nihari mixture slowly and gradually while constantly stirring it.
In another pan, fry 1 sliced onion until it is golden brown and cut a 1 inch piece of ginger into thin juliennss.
Heat some oil in a pan and add a teaspoon of chill powder into it. Take it off heat and pour it directly over the ready Nihari.
Top the Nihari with a generous sprinkle of chopped coriander leaves, ginger juliennes and the fried onions.