In a mixer-jar combine the coconut, mango pieces, green chilli salt and a little water and grind to make chutney.

Transfer into a bowl.

Heat oil in a tadka pan on medium heat, add oil, then add mustard seeds and allow them to crackle, now add curry leaves and red chilies and red chilli pwr turn off the flame. 

Pour the tempering all over the chutney

Serve Raw Mango & Coconut Chutney idlis,  Masala Dosa or Oats and Besan Cheela.