1. Wash 1/2 kg pork very well and cut into small pieces. add salt to taste.
2. Then add 1 tsp ginger garlic paste, 1-2 tbsp goan vinegar (or juice of 1 lime). let it aside to marinate for an hour.
3. After marinating, put it in a pressure cooker. add 1/2 cup water and pressure cook for 2 whistles.
4. In a pan, add 2 tbsp oil. then add 4 sliced onions and fry until slightly brown.
5. Next add 5-6 green chillies, slit in between until dark brown.
6. Remove the chillies and half of the onions and keep aside.
7. In the remaining onions, add thin strips of 1/2 inch ginger and 3-4 garlic cloves. fry it well.
8. Then add pressure cooked pork and fry for a minute or two.
9. Add pork stock from the pressure cooker. when it boils, add 1/2 tsp turmeric powder, 1 heaped tsp chilli powder, 1/2 tsp garam masala powder. mix it well.
10. Add 1 large chopped tomato. let it boil on medium flame until the water dries.
11.When water is nearly dried, add 2 tsp goan vinegar and 2-3 cubed and fried potatoes. mix lightly and let water continue to dry.
12. Towards the end add fried onions and chillies you had kept aside. mix well and switch off the flame.