To make broth, roughly chop root ginger, garlic
and spring onions and add to chicken stock. Bring to the boil over medium heat and simmer,
half covered for 30 minutes. Meanwhile, cook noodles in plenty of boiling
water, following packet instructions. Wash away starch and drain. Sprinkle 1 tablespoon sake and 2 tablespoons soy
sauce over pork and set aside. Parboil beans, then drain. Stir fry beans sprouts in a little oil over high
heat for 1 minute. Add beans and stir fry for 1-2 minutes. Season with salt and pepper and remove to a
plate. Add pork to pan and stir fry for 5-6 minutes
until well cooked.
Strain broth into another pan, discarding ginger,
garlic and spring onions. Season with remaining soy sauce and sake, salt
and pepper. Bring to the boil, add noodles and cook over
medium heat for 1 minute. Divide noodles between 4 individual noodle bowls,
keeping broth at a gentle simmer. Divide cooked ingredients between bowls. Pour broth over them and serve garnished with
chili oil, if wished.