In a small bowl, combine soy sauce, Mirin, and Worcestershire sauce.

Bring a large pot of water to a boil. Add the noodles and cook according to the directions on the packaging. Drain in a colander, and then rinse under cold water. Set aside in the colander to drain

Pour the oil into a large wok set over high heat. When just starting to smoke, add the onion. Stir-fry until onion is soft, about one minute. Add the pork and cook, stirring occasionally, until it is no longer pink. Add the cabbage and carrot. Stir-fry until the cabbage is starting to soften, one to two minutes.

Add the noodles, and stir-fry for a minute. Pour in the sauce and stir well. Stir-fry until the sauce has been absorbed, one to two minutes. Add the scallions, stir well, and then turn off the heat.

Divide the contents between two plates, and garnish with a sprinkling of bonito flakes. Season with salt and togarashi to taste.