Heat oil in a pressure cooker pan. Add mustard seeds, turmeric powder and asafoetida.
Add the chopped brinjals(eggplant/aubergine) and potato.
Mix and add salt as per taste.
Mix well. Add water and cover the lid with a whistle and pressure cook for 2 whistles on high and one whistle on low heat.
In the meantime prepare the masala. In a plate or bowl add groundnut powder, desiccated coconut, sesame seeds, red chili powder, coriander-cumin powder, garam masala, sugar, and a little salt.
Add chopped coriander and curry leaves. (i have used dried curry leaves).
Mix well.
Open the lid after the pressure cooker has cooled down.
Add the prepared masala and mix gently. (My husband likes the brinjal to be mushy and hence I have pressure cooked more than the time specified).
Simmer for 4-5 minutes till the masala is absorbed. The ringan batata nu shaak is ready.
Serve ringan batata nu shaak hot with roti, dhebra, paratha, rotla, puri, thepla, rice and dal, masala khichdi and kadhi.