Tentsuyu

Wipe the kelp with a cloth and soak in water for 30 minutes.
Heat over low heat and remove the kelp at 70-80°C.
Add the bonito flakes, simmer for 1-2 minutes and rub.
Add soy sauce, mirin and sugar to the dashi stock.
Heat over medium heat and bring to a boil.
Removed the heat and finished.