1. Add water, konbu and mirin to a container, keep in fridge for 6 hours to 2 days.
    • Water, 400ml
    • Mirin, 45ml
    • Konbu, 15g
  2. Bring mixture to a simmer for 10 minutes.
  3. Remove and discard konbu.
  4. Add sake, bring to boil for 10 minutes, or until the smell of alcohol subsides.
    • Sake, 100ml
  5. Add remaining ingredients, whisking to dissolve.
    • Salt, 50g
    • MSG, 10g
  6. Store in a container.