In a large pot, combine beef broth, water, and the bouillon cube.
Add cinnamon and star anise if using, along with onion, ginger, sugar, and fish sauce.
Bring everything to a boil, then reduce the heat and let it simmer gently for 20 minutes.
While your broth is simmering, cook the dried rice noodles in a separate pot, following the package instructions.
Drain and set them aside once cooked.
Once the broth has simmered, add the thinly sliced beef.
Allow it to cook until the beef is tender and fully done, taking care not to overcook.
Place a serving of cooked noodles into each bowl.
Carefully ladle the hot broth and beef over the noodles, ensuring each bowl is generously filled.
Serve the pho hot, with lime wedges, Thai basil, bean sprouts, cilantro, green onions, and hoisin sauce on the side.