In a bowl, marinate the pork cubes with vinegar, ginger, garlic, turmeric powder, red chili powder, and salt. Let it marinate for at least 30 minutes or overnight for more flavor.

Heat vegetable oil in a large pan or a Dutch oven over medium heat. Add cumin seeds and mustard seeds. Let them sizzle for a few seconds until fragrant.

Add the chopped onions to the pan and sauté until they turn golden brown.

Stir in the marinated pork and cook until it is nicely browned on all sides.

Add the tomato paste and stir well to coat the pork.

Reduce the heat to low and cover the pan. Let it simmer for about 1 to 1.5 hours, or until the pork is tender and cooked through, stirring occasionally.

Adjust the seasoning with salt if needed and garnish with fresh coriander leaves.

Serve hot with steamed rice, naan bread, or any other accompaniment of your choice.