Grab a large saucepan. Over medium heat, add in the mirin, sake, soy sauce, and brown sugar while stirring. Bring to a boil and then turn the heat off. Put the sauce into a bowl for later use.
Soak the udon noodles in water for about 10 minutes.
While the noodles soak, chop all of your ingredients, slice the beef, and set them aside. Cut the tofu into ¼ inch pieces. The beef must be sliced into almost paper-thin strips.
Heat up the vegetable oil in the pan. Cut the white parts of the scallion separately and fry them in oil for a couple of minutes.
Now add in the beef. Sear the beef for 20 seconds, and then add a small drizzle of sukiyaki sauce. Continue frying the beef until it starts to brown. Once it’s almost all brown but still has a bit of pink color, remove the meat from the pan and set it aside for later.
Add the remaining sukiyaki sauce to the pan and the 2 cups of dashi stock. Bring the liquids to a boil and add the tofu, napa cabbage, enoki mushrooms, and tong ho or parsley. Push the ingredients to one side of the pan.
Drain the udon noodles and add them to the other side of the pan. Cover the pot and bring everything to a simmer and let it cook for about 7 minutes.
Remove the lid and add the beef back into the pot. Now you can add the green parts of the scallions and poached eggs if you want.