Take the thin coconut milk in a pan(or a pressure cooker) and add the potatoes, onion, green chillies and ginger to it.
Add required salt, water and switch on flame.
Boil the potatoes till it turns soft and mushy. (2 whistles in pressure cooker)
Open lid, reduce the flame and add the thick coconut milk.
Heat through for about 2 min
Add coconut oil and curry leaves to the stew and switch off the flame.
Keep the pan covered for few minutes so that the flavours of the oil and curry leaves can be induced into the stew.