Boil the rice noodles in boiling water for 5 minutes, then drain.
Slice the beef thinly.
Thinly slice the onion and cilantro.
Pour water into a pot and add beef, onion, and aromatic ingredients to make the broth.
Place the cooked noodles in a bowl and pour the hot broth over them.
Top with beef, vegetables, and cilantro.
Serve with lime, chili sauce, etc., as desired.