This is an easy-prep sauce! All you need to do is mix in the ingredients after sautéeing the garlic. Even though the recipe uses such common ingredients, the taste is authentic.
I always hesitated tossing out the umami-rich oil from canned tuna, so I came up with this recipe to make good use of it.
Use the oil from the canned tuna. That's what gives it plenty of umami, and it is thrifty, too.
Enjoy Japanese food around the world.