Heat the oil or ghee in a large pot or pressure cooker over medium heat.
Add the sliced onions and sauté until golden brown.
Add the ginger-garlic paste and cook for a minute until fragrant.
Now add the beef pieces and cook until they are browned on all sides.
Stir in the Nihari masala, turmeric powder, red chili powder, and salt. Mix well to coat the meat evenly.
Pour in the water and bring it to a boil. If using a pressure cooker, cover it and cook on medium heat for about 30 minutes. If using a regular pot, cover it and let it simmer on low heat for 3-4 hours until the meat is tender.
If you prefer a thicker gravy, mix the wheat flour with a little water to make a smooth paste. Stir this mixture into the Nihari and cook for an additional 10 minutes to thicken the gravy.
Garnish with fresh ginger and cilantro leaves.
Serve hot with naan bread or rice and lemon wedges on the side.