- Juice of 4 lemons
- 1/3 cup plus 2 tablespoons rice vinegar
- 1 cup dark soy sauce
- 2 tablespoons tamari sauce
- 3 tablespoons mirin
- 1/3-ounce dried bonito flakes
- 2-inch square giant kelp (konbu)
Combine all ingredients in a bowl and let stand 24 hours. Strain through a cheesecloth and store up to 3 months in a cool, dark place, or in the refrigerator.