Marinate the pork: In a bowl, mix pork cubes with vinegar, salt, and turmeric. Cover and refrigerate for at least 1 hour (overnight for best flavor).

Prepare the spice paste: Dry roast cumin, coriander seeds, black peppercorns, and dried red chilies in a pan until fragrant. Grind into a fine powder using a spice grinder or mortar and pestle.

Cook the aromatics: Heat oil in a large pot over medium heat. Add mustard seeds and let them splutter. Add chopped onions and sauté until golden brown.

Add ginger and garlic: Stir in minced garlic and grated ginger. Cook for 1-2 minutes until fragrant.

Combine spices and pork: Add the ground spice mix to the pot, followed by the marinated pork. Stir well to coat the meat with spices.

Simmer the vindaloo: Pour in water, add sugar, and bring to a boil. Reduce heat to low, cover, and simmer for 1-1.5 hours until pork is tender and sauce thickens.

Adjust seasoning: Taste and adjust salt or spice level if needed. Garnish with fresh cilantro before serving.