01 - Combine beef slices with 1 tablespoon soy sauce, cornstarch, sesame oil, and black pepper in a bowl. Mix thoroughly and let marinate for 15 minutes.
02 - Heat a small amount of oil in a large pot over medium heat. Add the white part of green onions, minced garlic, and sliced ginger. Sauté until fragrant, approximately 1 minute.
03 - Add the marinated beef slices to the pot and stir-fry until just browned, about 2 to 3 minutes. Remove beef from the pot and set aside.
04 - Pour beef broth into the same pot. Add soy sauce, oyster sauce, optional dark soy sauce, star anise, cinnamon stick, sugar, and the sautéed aromatics. Bring to a boil, then reduce heat and simmer for 20 minutes.
05 - Cook the noodles according to package directions. Drain and set aside.
06 - Add bok choy and julienned carrot to the simmering broth. Cook for 2 to 3 minutes until just tender. Return the beef to the pot and heat through for 1 to 2 minutes.
07 - Distribute cooked noodles into serving bowls. Ladle beef, vegetables, and broth over the noodles. Garnish with bean sprouts, green parts of spring onion, cilantro, and red chili slices if desired. Serve immediately while hot.