In a pot add ¼ cup oil then spread first layer of sliced potato then second layer of sliced brinjal and finally a layer of chopped tomatoes. Add all spices and top with remaining oil. Cover and cook for 5 minutes. Then mix all vegetables and spices very well.
Cover the pot and slow cook for 25 minutes on lowest flame when potatoes are tender and oil separates. Add tamarind pulp in the last and mix. (Keeping checking after every 10 minutes, and add only ¼ cup water if needed.)
Garnish with chili slices and fresh coriander. Serve with lemon slices, pickle and whipped yogurt.