"Hana Katsuo" is the skipjack tuna shavings widely used in Japanese dishes for final taste enhancer.
1. Boil 600cc of water
2. Add 20g of "Hana Katsuo" and bring the water back to boil a few seconds, and turn off the heat.
3. after the "Hana Katuso" is settled down, straing the stock through a fine strainer.