Slice beef against the grain into thin strips and marinate with soy sauce, brown sugar, cornstarch, sesame oil, and minced garlic for at least 15 minutes.

Heat sesame oil in a large pot over medium heat, add minced garlic and sliced ginger, and sauté for about 1 minute.

Pour in beef broth and water, add soy sauce and mirin, and drop in star anise and cinnamon stick. Let it simmer for 15-20 minutes.

Remove ginger slices, star anise, and cinnamon stick before serving.

Boil water and gently lower eggs in. Set timer for 6 minutes and 30 seconds, then prepare an ice bath.

Once done, transfer eggs to ice water for 5 minutes, peel carefully, and slice in half.

Wash and trim bok choy, slice mushrooms, and chop green onions, separating white and green parts.

Boil water for noodles and cook according to package instructions, then drain.

Sear marinated beef in a hot skillet until caramelized, about 1-2 minutes per side.

Place cooked noodles in bowls, ladle hot broth over them, and add bok choy and mushrooms.

Arrange sliced beef, top with soft-boiled eggs, sprinkle green onions, sesame seeds, and drizzle with sesame oil before serving hot.