Makes about 2 cups

• 2 cups water
• 2-inch piece kombu (dried black kelp)
• 1/2 cup loosely packed dried bonito flakes (katsuobushi), optional

1. Warm the water and kombu over medium heat: Combine the water and kombu in a 1-quart saucepan and set over medium heat.
2. Remove the kombu as the water comes to a boil: Remove the kombu from the water just before it comes to a full boil. (Boiling the kombu can make the broth bitter and a bit slimy.)
3. Add the bonito flakes and simmer: Add the bonito flakes, if using, and let the water come to a rapid simmer. Continue simmering for about 1 minute.
4. Steep the bonito flakes off the heat: Remove the pan from heat and let the bonito steep in the broth for an additional 5 minutes.
5. Strain the broth: Strain the bonito flakes from the both. Add additional water, pouring through the strained bonito, if needed to make 2 cups.
6. Use or store the broth: The broth can be used immediately, refrigerated for up to a week, or frozen for up to 3 months.

• For vegetarian dashi: The dashi is ready to be used after removing the kombu. No additional boiling or steeping is necessary.
• For more deeply flavored dashi, steep the kombu in the water overnight before continuing with the recipe.

https://www.thekitchn.com/how-to-make-japanese-dashi-broth-cooking-lessons-from-the-kitchn-57749