Cut the cilantro so that the food processor / blender can handle it easily.
If using mint, remove the leaves from the stem.
Cut the kaffir lime leaves into thin strips so that the food processor can handle it easily.
Finely chop the lemon grass before blending as this may be sometimes a little tough to blend.
In a food processor / blender, add lime juice, cilantro, mint, kaffir lime leaves, lemon grass, Thai curry paste and fish sauce and blend. DO NOT ADD THE CHILI.
If the paste is not spicy enough, you can add the chopped fresh chili or add additional green curry paste to taste.