Cut off the bottom of your greens and cut them into 2 inches (5cm) pieces.
Cut the aburaage into 3/8 inch pieces (1 cm).
In a medium saucepan, add dashi and aburaage and bring it to a simmer. Once simmering, add soy sauce and salt.
Mix all together and then add the dense parts (stems) of the greens.
Mix all together and cook for 1-2 minutes, and then add the tender parts (leaves) of the greens.
Mix together and simmer on low heat for 3 minutes (depending on the ingredients). Transfer the dish (with cooking liquid) to an airtight container and let cool to steep.
To Serve and Store
You can serve right away, but I recommend resting the dish for overnight. You can keep in the refrigerator for up to 3-4 days or freezer for up to 1 month. Reheat before serving, or you can serve at room temp or chilled (which I prefer).