Heat mustard oil in a non stick kadai. Add green cardamoms and sauté for a minute. Add onion and sauté lightly.
Cut the bamboo shoots into cubes. Add green chilli paste, turmeric powder, red chilli paste, tomatoes and chicken to the kadai and sauté for 2 minutes. Add salt and mix.
Add 1½ cups water and bamboo shoots. Cover and cook for 10-15 minutes. Add coconut milk and cook for 4-5 minutes.
Transfer into a serving bowl and serve hot