In a bowl, mix 500 grams of mutton pieces with 1/2 cup of vinegar, 1 teaspoon of turmeric powder, and salt as per taste. Marinate for at least 1 hour or overnight for better results.
In a pan, dry roast 5-6 dry red chilies, 1 tablespoon of coriander seeds, 1 teaspoon of cumin seeds, 1/2 teaspoon of black peppercorns, 4-5 cloves, and 1-inch cinnamon stick. Roast until fragrant and let it cool.
Grind the roasted spices into a fine paste using a mixer grinder, adding a little water if needed.
Heat 3 tablespoons of oil in a heavy-bottomed pan or pressure cooker. Add 1 finely chopped onion and sauté until golden brown.
Add the ground spice paste to the pan and cook for 2-3 minutes, stirring continuously.
Add the marinated mutton pieces to the pan and cook for 5-7 minutes, stirring occasionally.
Add 1 cup of water, mix well, and bring the mixture to a boil. If using a pressure cooker, cook for 4-5 whistles or until the mutton is tender. If using a pan, cover and cook on low heat for 45-60 minutes, or until the mutton is tender.
Adjust the salt and add 1 teaspoon of sugar to balance the flavors. Cook for another 2-3 minutes.
Garnish with chopped coriander leaves and serve hot with steamed rice or Indian bread.