1. Pressure Cook the Potatoes with turmeric powder and salt for 3 whistle. Peel off the skin and mash it in a bowl and set aside.
2. Chop the onion,tomato,ginger,coriander leaves ( optional) finely and split the green chilly and set aside .
3. Heat 3 tbsp oil in a kadai , splutter mustard seeds,jeera, uraddal, channadal. When the dals turn light brown , add split green chilly, finely chopped onion and ginger.
4. Saute till the onions turns translucent , add the chopped tomato and a pinch turmeric powder. Saute till the tomatoes turn mushy.
5. Add 1/2glass Water and mix well.,till the raw smell goesoff. Now add the mashed potatoes , mix well.
6. Finally garnish with finely chopped coriander leaves. Serve hot with Poori, Chappathi.
Note_:
This masala can be used as a stuffing for Masala dosa , Aloo bonda , Stuffed paratha .