To make green curry paste, grind green chillies, shallots, garlic, galangal, lemon grass, lemon rind, coriander roots, coriander seeds, cumin seeds and salt to a fine paste. Blanch all the vegetables. Tie lemon grass in a muslin cloth to make a bundle. Crush it slightly.
Heat a non-stick pan, add green curry paste and roast for one minute. Add the blanched vegetables, lemon juice and cook for three to four minutes stirring continuously. Add three cups of water and continue to cook. Add lemon grass bundle and cook for three to four minutes till the lemon grass flavour is imparted. Remove the bundle and add salt and coconut milk. Simmer for a minute. Add basil leaves and take off the heat.