In a large pot, combine beef broth, halved onion, sliced ginger, star anise, cinnamon stick, fish sauce, and soy sauce. Bring to a boil over medium-high heat.

Reduce heat to low and let the broth simmer for at least 30 minutes to allow the flavors to meld. Skim off any foam that rises to the surface.

While the broth simmers, cook the rice noodles according to package instructions. Drain and set aside.

After the broth has simmered, strain it through a fine-mesh sieve to remove solids. Return the clear broth to the pot and keep it warm over low heat.

In serving bowls, divide the cooked rice noodles and top with raw beef slices. Pour the hot broth over the noodles and beef to cook the meat.

Garnish each bowl with bean sprouts, fresh basil leaves, jalapeño slices, and lime wedges. Season with salt and pepper to taste.

Serve immediately and enjoy!