Cook the noodles and soya beans in a large saucepan of lightly salted boiling water for 4–5 minutes, or according to the noodle packet instructions. Drain well, then return to the pan and add the spring onions. Cover and keep warm.
Heat a frying pan until hot, add the sesame seeds and dry-fry over a medium heat until lightly golden, then remove from the pan and set aside.
Peel and grate the root ginger into a bowl, then stir in the remaining ingredients and mix well. Pour the dressing over the noodle mixture and toss to mix well.
Ladle into warm bowls, scatter over the sesame seeds and chopped coriander and serve.