Bring water to the boil and add oil and salt.Blanche the sliced beans for a minute or so. Remove the beans and immediately place in chilled water, drain and put aside.
Boil water and cook the rice noodles.
Remove the noodles and place in chilled water, drain and mix in a small amount of the oil to stop the noodles sticking together.
Add oil to the wok and stir-fry the sausage strips on low heat.
Remove the sausage strips and put aside.
To the hot wok, add the carrot strips, sprinkling with a little water and stir to soften.
Add onion and a little salt, and continue to stir-fry until the onion is soft. Remove from the pan and put aside.
Add more oil to the wok and stir to cover the sides, pouring out excess oil.On low heat, stir fry the rice noodles using two chopsticks, making it easier to separate them so that they cook evenly. Add egg strips, and return carrot, onion and sausage to the wok and stir-fry evenly.
Add light soy sauce and dark soy sauce to taste and to add color.
Lastly, add the beans and stir-fry evenly.
