6 c. water
1 (3 inch) sq. dried kelp (kambu)
1/2 c. dried flaked bonito (katsuobushi)

In large saucepan bring water to boiling. Meanwhile wash dried kelp under cold water. Add to water as it comes to a boil. Boil and stir gently 3 minutes. Remove kelp and discard. Stir in dried flaked bonito; simmer 10 minutes. Remove from heat and do not disturb for 2 minute to allow flakes to settle to bottom.