Mint leaves are not used for making chutney in Kathmandu Valley where they grow wild, but they are generally used in the Terai region of Nepal.

Ingredients
1 cup of green mint leaves
2 small garlic cloves
1/4 teaspoonful of chili powder or 1/2 green chili
1 teaspoonful of salt
2 tablespoons of mustard oil
1/2 teaspoonful of fenugreek seeds
1/2 teaspoonful of turmeric
Juice of one or two lemons

Process
Grind mint leaves and garlic in a mortar.  Add salt and chilis.  Squeeze one or two lemons for juice.   Heat the mustard oil in a small frying pan and fry the fenugreek seed till they become black.  Add the turmeric and turn with a spoon.  Now add the mint and garlic mixture.

Time required 10- 15 minutes