Step 1In a pot over a portable electric or gas cooktop (or just your regular stove) over medium heat, add 2 tablespoons sake, ¼ cup mirin, 1 tablespoon brown sugar, and ¼ cup soy sauce in a saucepan. Bring to a boil, turn off the heat, make sure all the sugar is dissolved, and transfer to a bowl.Step 2Then prepare all your sukiyaki ingredients––the tofu slices, rehydrated shiitake mushrooms, enoki mushrooms, napa cabbage, tong ho, and scallions. Set aside on a plate. Soak the dried vermicelli noodles in water for 10 minutes.Step 3Heat 1 tablespoon vegetable oil in the pan. Fry the white parts of the scallions in the oil for 2 minutes. Chop the green parts of the scallions finely and set aside.Step 4In the pan with the scallions, add the sliced beef. Sear the beef for 10 seconds, and add a drizzle of your sukiyaki sauce. Fry the meat until it just begins to brown––it should still be a bit pink. Remove from the pot and set aside.Step 5Add the rest of your sukiyaki sauce and 2 cups stock. Bring to a boil, and add the tofu, mushrooms, napa cabbage, and tong ho to the pot in sections. Also drain the vermicelli noodles you soaked and add them to the pot. Cover the pot and bring to a boil. Simmer until the ingredients are cooked through, about 5-7 minutes.Step 6Remove the cover, add the beef back to the pot. Sprinkle with the chopped scallions, and enjoy with rice and egg yolk (if desired).