Pour the mirin into a sukiyaki pan, cast–iron pan, or pot, but do not oil it first as you would for sukiyaki. Bring to a rolling boil for a few minutes to burn off the alcohol. Add the tamari and the chicken, vegetables, and other prepared ingredients a little at a time, and cook until done. Thin out the sauce with water as needed.
To serve, use a beaten egg as your dipping sauce if you want.
Optional ingredients to add if you want:
1. Shiitake mushrooms, stemmed and cut in half
2. One or two bunches of mitsuba (trefoil), cut off ends, and cut into 2-inch pieces