Source: The Martha Stewart Show, January 2010
- 2 (6-inch) pieces kombu
- 1 1/2 ounces dried, shaved bonito (about 3 packed cups)
Place 8 cups of water in a large pot. Add kombu and let steep for 30 minutes.
Place pot over medium heat and bring to a boil; remove kombu and discard. Add 2 tablespoons water and bonito; stir until well combined. When liquid returns to a boil, immediately reduce heat to low; let simmer for 5 minutes, skimming surface as necessary.
Remove pot from heat and let steep 15 minutes. Strain through a fine mesh sieve or cheesecloth; do not press down on or squeeze bonito flakes. Discard solids.