Ingredients
       4  big potatoes boiled and cut into cubes 
       2  medium onion(s) sliced finely 
       1  big tomato(es) chopped finely 
       1  teaspoon(s) red chilli powder or as per taste 
       ½  teaspoon(s) tamarind paste or as per taste 
       4  tablespoons oil 
       salt to taste, coriander leaves to garnish

Preparation
1.   Heat oil on in a pan on a low flame for about 2  minute(s). 
Add mustard and when it splutters add finely sliced onions and 
fry on till golden brown. 
2.   Now add red chilli powder and fry for a few more seconds on 
low heat till you get a good roasted aroma. 
3.  Add chopped tomatoes and fry again on medium / low heat for  
3minute(s) or till the tomatoes are tender and the oil has left 
the sides of the pan. 
4.  Now add the tamarind paste and when  the mixture starts to 
boil add boiled potato cubes. 
5.  Sprinkle some water and salt to taste. Mix thoroughly. Cover 
and keep on low heat for about 4 minutes till the gravy boils 
nicely. Remove from the stove and garnish with coriander leaves. 
Serve hot and enjoy with idli, dosas, roti, chapathi, puris.