This is fairly quick to make - ten minutes or so - but the effect is profound. The quantities I give are small as this sauce won't keep for long. If you want something that will, try green chilli preserve. As always watch what you do with your hands after handling chillies - don't stick them anywhere sensitive.
Ingredients
4 or 5 fresh green chillies
A small bunch of green coriander
A sprig of mint
1 small clove of garlic
Juice of half a lemon
Half a small glass of water
A quarter teaspoon of salt
Chop the solid ingredients roughly, then smash them all up, with the salt, in a pestle and mortar. Keep going at it until the mixture is fairly smooth, then add the lemon juice and some water. Be warned - this is mean stuff.