- 1 cup light soy sauce
- 1 cup sour orange or yuzu juice*
- ¼ cup mirin*
- One 2-inch piece kombu*
- 1 tablespoon bonito flakes*
*Note: Ready-made ponzu sauce may be bought from Asian markets; the Mikusan brand is a good choice. If you want to make ponzu yourself, look for sour oranges in Latin or Caribbean market. The Japanese citrus fruit yuzu or its juice, along with mirin (rice wine), kombu (dried kelp), and bonito flakes are available from Japanese markets and some specialty-food stores, health food stores, or the Asian food section of well-stocked supermarkets.
Combine the soy sauce, juice, and mirin in a nonreactive container. Stir in the kombu and bonito flakes cover and refrigerate for 2 days.
Remove from the refrigerator and strain through a fine-mesh sieve before serving.