Heat the 1 tablespoon sesame oil in a large pot over medium-high heat. Add the ½ pound beef tenderloin, and sear it just barely on all sides, it will finish cooking in the broth.
Remove the seared meat and set aside. Add the 1 medium yellow onion,1 large knob of ginger, and 4 cloves garlic, to the pot and cook, stirring occasionally, until everything is tender and toasted.
Add the 4 cups beef broth, 4 cups water, 1 cinnamon stick, 1 whole star anise, 1 clove, ½ teaspoon coriander, 1 tablespoon fish sauce, 2 teaspoons hoisin sauce, 2 teaspoons soy sauce, and stir everything together and bring it to a gentle boil.
Add the beef back to the pot, reduce the heat to low, and simmer until it is cooked. While the beef is cooking, boil the 8 ounces rice stick noodles, according to the package directions, drain, and set aside.
Remove the onions, ginger, garlic, cinnamon stick, star anise, and clove from the soup and discard.
Serve the soup in bowls with a serving of cooked noodles and the suggested toppings.