Heat the oil in a wok and fry the ginger, lemongrass and garlic until fragrant. Add the spices and onion, followed by the briyani spice mix, chilli powder and turmeric powder. Add the chicken and seasoning, and mix well. Sprinkle in a little water to moisten the mixture.
Transfer the fried ingredients into an electric rice cooker pot. Add the rice and pandan leaves, and pour in water and evaporated milk. Cook rice.
When rice is done, add the long beans, fluff up the rice, and allow to stand for 10 to 15 minutes before serving.