Prepare all sukiayaki ingredients, including tofu slices, shiitake mushrooms, enoki mushrooms, napa cabbage, tong ho, and scallions. Set aside on a plate.
Soak dried vermicelli noodles in water for 10 minutes.
Heat vegetable oil in a pan. Fry white parts of the scallion in the oil for 10 minutes. Chop green parts of scallions finely and set aside.
Add sliced beef to the pan with the scallions. Sear the beef for 10 seconds and add a drizzle of sukiyaki sauce. Fry the meat until it begins to brown; it should still be slightly pink. Remove from pot and set aside.
Add more sukiyaki sauce and stock. Bring to a boil.
Add tofu, mushrooms, napa cabbage, and tong ho to the pot in sections. Drain vermicelli noodles and add them to the pot..
Cover pot and bring to a boil. Simmer until the ingredients are cooked through (5-7 minutes).
Remove the cover and add the beef back to the pot. Sprinkle with chopped scallions, and enjoy with rice and egg yolk (if desired).