Cook the potatoes in a pressure cooker in lots of water on high flame for three whistles.
Switch off, allow the pressure to go by itself. Open the cooker, drain the potatoes.
Peel and slice in to medium sized pieces. Set aside.
In a kadai, heat the oil. Splutter mustard and cumin seeds.
Add the urad dal and fry for a minute. Add the curry leaves and fry for another minute.
Now add the masala powders and stir well. Add the potatoes and give it a good mix.
Leave it on a low flame for about 5-6 minutes. Add the salt and mix well again.
Serve warm as side dish with rice and curry!