Thinly slice the flank steak against the grain into very thin strips and set aside.
Place the sliced ginger and star anise in a medium pot over medium-high heat, charring them for 2 minutes until fragrant.
Pour the beef bone broth into the pot and add the cinnamon stick and fish sauce.
Bring the broth to a boil, then reduce heat and simmer for 15 minutes to develop the flavors.
While the broth simmers, cook the rice noodles in a separate pot of boiling water according to package directions, then drain and place in a large serving bowl.
Season the simmering broth with sea salt and black pepper, then remove the ginger, star anise, and cinnamon stick.
Arrange the raw beef slices over the cooked noodles in the bowl.
Pour the boiling hot broth directly over the beef slices to cook them instantly.
Top the soup with bean sprouts, cilantro, Thai basil, and sliced jalapeño.
Squeeze the lime wedge over the bowl and serve immediately.