01 - Combine beef slices with 1 tablespoon soy sauce, cornstarch, sesame oil, and black pepper in a bowl. Mix thoroughly and marinate for 15 minutes.
02 - Heat a small amount of oil in a large pot over medium heat. Add the white parts of green onions, minced garlic, and ginger slices. Sauté until fragrant, about 1 minute.
03 - Add marinated beef slices to the pot and stir-fry until browned, approximately 2 to 3 minutes. Remove beef and set aside.
04 - Pour beef broth into the 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 - Prepare noodles according to package instructions, drain, and set aside.
06 - Add bok choy and julienned carrots to the simmering broth. Cook for 2 to 3 minutes until just tender. Return beef to the pot and heat through for 1 to 2 minutes.
07 - Divide cooked noodles into serving bowls. Ladle beef, vegetables, and broth over the noodles.
08 - Top with bean sprouts, green parts of spring onions, chopped cilantro, and optional red chili slices. Serve immediately while hot.