Ingredients:

Tomatoes                               : 3 medium
Salt                                 
Curd                                       : 1/2 cup

For grinding

Green chillies                        : 4
Shredded coconut                  : 1 cup
Mustard seeds                       : a pinch

For seasoning:

Mustard seeds                        : 1/2 tsp
Red chillies                            : 2 split into 2
Curry leaves
Oil                                          : 1 tbsp                          

Method:

Grind coconut and green chillies together, towards the end of it add mustard seeds and grind it.  Boil tomatoes with salt till tomatoes become soft.  Add the ground coconut mixture and boil for 3 mins . Finally add the curd and mix well , before boiling remove from fire.
Season with mustard seeds, chillies and curry leaves.