Rinse the beef or lamb shanks thoroughly under cold water. Pat them completely dry with paper towels. This ensures good searing and prevents steaming, which is crucial for flavor development.

Dice 2 medium onions finely. Mince 2 inches of fresh ginger and 3 green chilies for garnish later. Roughly chop 1/2 cup of fresh cilantro for garnishing.

Heat 4 tablespoons of oil or ghee in a large, heavy-bottomed pot or Dutch oven over high heat. Once shimmering, add the dried meat in batches, ensuring not to overcrowd the pot. Sear until deeply browned on all sides.

Remove the seared meat and set aside. Add the diced onions to the same pot, reducing heat to medium. Cook until translucent and lightly golden. Add the ginger-garlic paste and Nihari masala, stirring for 1-2 minutes until fragrant.

Return the seared meat to the pot. Add 1/2 cup plain yogurt (if using, it helps tenderize) and 1.5 teaspoons of salt. Pour in 6 cups of water, ensuring the meat is mostly submerged. Bring to a boil, then reduce heat to very low, cover tightly, and let it simmer.

While the Nihari simmers, prepare the Gobi Chawal. Roughly chop the small onion for Gobi Chawal. Grate the entire large cauliflower head using a box grater or pulse it in a food processor until it resembles rice grains.

Heat 2 tablespoons of ghee or oil in a large frying pan over medium heat. Add 1 teaspoon cumin seeds and let them splutter. Add the chopped onion and cook until translucent. Stir in 1/2 teaspoon turmeric powder and 1/2 teaspoon salt.

Add the grated cauliflower and 1 cup of green peas to the pan. Sauté for 5-7 minutes, stirring occasionally, until the cauliflower is tender-crisp. Avoid overcooking to maintain texture.

Continue simmering the Nihari for 2.5 to 3 hours, or until the meat is extremely tender and falling off the bone. Check occasionally to ensure liquid isn't evaporating too quickly; add a little hot water if needed.

In a small bowl, whisk 4 tablespoons of all-purpose flour with 1/2 cup of cold water until a smooth slurry forms. Gradually whisk this slurry into the simmering Nihari gravy. Cook for another 10-15 minutes, stirring occasionally, until the gravy thickens to your desired consistency.

Ladle the hot Nihari Gosht into serving bowls. Garnish generously with the minced fresh ginger, green chilies, and chopped cilantro. Serve immediately with the Gobi Chawal and lemon/lime wedges on the side for squeezing.