2Mix the 150 ml soy sauce, mirin, 150ml water, 1 sliced spring onion, the ginger, chilli flakes, peppercorns and sesame seeds in a deep container. Peel the eggs and lower them into the soy sauce mix. Put the lid on the container, then chill for at least 3 hrs. Will keep chilled for up to two days.
3Mix the miso, 2 tbsp soy sauce, rice wine vinegar, honey and coriander in a medium bowl. Boil the soba noodles following pack instructions and rinse well with cold water to keep them from sticking. Reserve some of the noodle cooking water.