1. Prepare the ingredients as above.
2. Pound together in a pestle and mortar [or you can use a blender] the ginger, lemon grass, galangal, garlic and five spice powder.
3. Heat the oil in a large saucepan or wok, fry the mustard seeds with the poppy seeds over a high heat until they pop [about 1 minute].
4. Add the chopped onion, cinnamon, ground spices and the curry leaves and fry for a further one minute.
5. Add in the remaining spices, mix well and fry for a further one minute before adding the lemon juice, chicken pieces and salt to taste. Bring to the boil, reduce the heat and then cover and simmer for ten to 15 minutes.
6. Stir in the coconut milk and then add the diced potato, chopped tomatoes and 300 millilitres of water and cook for a further 10 minutes. (longer for a thicker sauce). Remove from the heat, add the oyster sauce, stir in well and set aside.
7. Heat a small pan and prepare the final flavouring; heat the oil and add the curry leaves, mustard seeds and chopped shallots. Fry, stirring constantly, until the mustard seeds pop.
8. Return the curry to the heat, pour in the final flavouring, stir well and heat through. Serve with bread, chapati or rice.
For a thicker sauce you can add one or two powdered Macadamia nuts together with the coconut milk.
