Place the beef in the freezer for 20 minutes to make it easier to slice.
Under a broiler or over a gas flame char the onion and ginger for 5-7 minutes until they just start to blacken.
Add them to a large soup pot with the crushed garlic, fish sauce, and coconut aminos.
Pour in the broth.
Set the pot over medium high heat and bring to a boil.
Reduce to a simmer and cook 30 minutes.
Raise the heat to high to bring to a boil before adding the broth to the bowls.
Prepare your toppings and noodles.
Follow this guide for preparing the noodles.
Once the broth has cooked 30 minutes and you have brought it back up to a boil carefully ladle it into the bowls on top of the noodles and beef.
The beef should start to turn brown immediately.
Top the soup with your desired toppings.