Shabu-shabu style with tuna

Dashi is the basics for Japanese cuisine. It is said that there is the best dashi, and there is a second dashi. The first dashi is turned off at a temperature below 100°C and the remaining heat exudes the umami flavor, while the second dashi uses the ingredients used for the first dashi to bring it to a boil to give it a umami flavor. At home, you don't need to be the number two. It's often thought that dripping dashi is a hassle, but it's surprisingly easy to make. Put the ingredients in the water and leave it for a day, and that's enough to make the soup stock. If it's not enough, boil it and get even more delicious dashi. It has a richer flavor than the best flavor that comes out from the residual heat...