Char the onion and ginger over an open flame or in a dry pan until blackened to release their oils.
In a large pot, combine the beef bone broth, star anise, charred onion, ginger, and sea salt.
Bring the broth to a gentle boil, then reduce heat and simmer for 20 minutes to develop the flavor.
While the broth simmers, cook the rice noodles according to package directions and set aside.
Thinly slice the raw eye of round steak against the grain into paper-thin pieces.
Strain the aromatics from the broth and stir in the fish sauce and black pepper.
Place the cooked noodles in a large bowl and top with the raw beef slices.
Pour the boiling hot broth directly over the beef to cook it instantly, then garnish with bean sprouts, basil, lime, and jalapeno.