To Prep
Fill a clay pot or large pot two-thirds full with water. Add kombu in the water and let it soak for at least 30 mins.
Meanwhile, combine all ingredients for the dipping sauce in a small bowl and set aside.
Clean and cut vegetables.
Arrange all the ingredients on a serving plate. Set a portable gas burner and place ingredient plate on a table. Give each guest a bowl of rice, an empty bowl for cooked food, and a sauce dish for the shabu shabu dipping sauce.
To Cook
Bring the broth with the soaked kombu to a boil. Add stem part of napa cabbage and shungiku, leek, carrots, some mushrooms, and tofu. You want to start with the ingredients that take the longest to cook.
Now bring the pot of boiling broth to the table. Each person cooks their beef by dipping a slice of beef in the boiling broth with chopsticks. Swish it gently back and forth until the meat changes colour, about 10 secs will do.
Enjoy the meat by dipping in the sauce.
Add remaining ingredients as necessary in the boiling broth and simmer for a few minutes.
End the meal with udon noodle. When most or all of the ingredients are taken out from the broth, add udon noodles in the pot and cook for a few minutes. Flavour udon with just bit of salt and white pepper.