Ingredients
3 strips (about 6 inches each) kombu, wiped with a dry cloth
2 cups bonito flakes
1 cup dashi
3/4 cup soy sauce
1/4 cup plus 2 teaspoons mirin
4 1/2 tablespoons lemon juice
1 1/2 teaspoons grated peeled fresh ginger
1 1/2 teaspoons grated daikon
Preparation
Make dashi: Combine kombu and 6 cups cold water in a medium saucepan and bring to just under a boil; remove from heat. Using tongs, remove kombu; discard. Sprinkle bonito flakes into the pan and let steep until they sink to the bottom, about 3 minutes. Strain liquid through a fine sieve. Dashi can be kept in an airtight container in the refrigerator up to 4 days.
Make dipping sauce: mix together dashi, soy sauce, mirin, lemon juice, ginger, and daikon in a bowl to combine.