In the same pan add the onions,ginger garlic,green chillies and saute well.add the capsicum and saute for 1 min then add the chilli powder,tomato sauce,soya sauce,vinegar and salt to the onion mix.into this mixture add pork pieces and mix well.finally add the chopped tomatoes (remove the seeds if the tomato).add the sugar and pepper powder at the final stage and mix well.