Saute half the onion to golden brown. Add ginger garlic, curry leaves and saute.
Add garam masala, red pepper, turmeric powder and salt. Cook for 2 minutes and add pork pieces and 4 tsp vinegar.
Lower the heat to medium. Cook for 45 -50 min.Stir occasionally until all the liquid is gone.
Saute the rest of the onion to a fairly dark brown color. Add paprika or kashmiri chilli, then add diced tomatoes and vindallu paste.
After 2 minutes, add the cooked pork and keep cooking for 5 more minutes under low heat. Make sure the lid is on. Serve hot with rice, chapathi or puri.