Separate the mint leaves and the coriander leaves from their stems and wash them thoroughly in several changes of water
In a little oil, saute the slit green chillies just for a few seconds. Next saute the mint leaves for half a minute till the raw smell goes and the mint leaves wilt. Remove and keep aside to cool.
In a mixer, without adding any water, grind together coconut gratings, green chillies, finely chopped ginger, garlic and lime juice.
Once the green chillies and the other ingredients are finely crushed, add the mint leaves and coriander leaves, and blend them to a fine paste adding very little water and the required amount of salt. Your Mint Chutney is ready.
Make the sandwiches by applying butter on one slice and the mint chutney on another slice. Put them together. Cut diagonally before serving. You can opt to cut the edges of the bread though I prefer not to.