Heat a wok or large frying pan over high heat and add the oil. Add the courgette, garlic, ginger and stir-fry for one minute. Add the rest of the ingredients. Reduce the heat and simmer for three minutes over low heat.
Cook the noodles in a large pot of boiling water according to the pack instructions. Drain them well in a colander. Divide the noodles into individual bowls and ladle the sauce over them. Serve at once.