This is an uncomplicated simmered Kyoto-style dish lightly seasoned with salt and mirin. It's a versatile recipe that works for any greens, not just komatsuna.
This is our family recipe for simmered greens in a mild broth (nibitashi).
To achieve the classic Kyoto-style lightly colored broth, I used usukuchi soy sauce. Regular soy sauce works as well.
Enjoy Japanese food around the world.