For the sauce, heat a wok or large frying-pan over high heat until hot. Add the oil. When it is very hot and slightly smoking, add the garlic, ginger and spring onions. Stir-fry for 15 seconds, then add the minced pork.
Stir well to break up all the pieces and continue to stir-fry for about 2 minutes, or more, until the pork loses its pink colour. Add the remaining ingredients, except the noodles, stirring all the time. Bring the mixture to the boil, turn the heat down to low and simmer for 5 minutes, adding a little water if it looks too dry.
Plunge the cooked noodles into a bowl of boiling water from the kettle for 30 seconds, or until they are just heated through. Drain them well in a colander or sieve.
Tip the noodles into a large serving bowl and pour the hot sauce over the top.
Sprinkle spring onions on top, mix everything together well and serve immediately.