Heat 1 tbsp olive oil in a large pot with fitted lid on med-high heat. Saute onion, garlic and ginger for 2-3 min, until fragrant and softened.
Add soy sauce, lime juice, sriracha, cinnamon, nutmeg and star anise stirring to combine. Add broth, bringing to a boil. Simmer for 30 minutes with the lid on. During this time, garnishes can be chopped and prepared.
After preparing garnishes, slice steak very thinly across the grain and set aside with other garnishes. Optionally, you can sear steak for 1-2 minutes per side if you don't want to add the beef to the broth when it's raw (it will cook in the hot broth if sliced thinly enough).
Drain broth into a large pot using a mesh strainer, then put pot with broth back on high heat, bringing to a boil. Add rice noodles, cooking for 1-2 minutes. If possible, remove noodles from the broth to prevent them from soaking up the broth. This is especially important if you want leftovers - store the broth and noodles separately in this case.
Serve the soup in large bowls with noodles, broth, steak, and garnishes. Beef will cook as it sits in broth. Enjoy!