Making the beef broth: Add coriander seeds, fenny seeds, cloves, star anise and cinnamon to a spice container. Add beef short ribs, onion, fish sauce, pepper powder, sugar water and spices in a pot. Bring it to a boil then turn down the heat, cover it with the lid and simmer for 3 hours.
Cooking the noodles and bean sprouts: Boil the noodles in the hot water until soften, and set them aside. Cook the bean sprouts in the remaining water for 10 seconds.
Assembling ingredients: Add beef, beef broth, cooked noodles, and vegetables together. Then top it with coriander, onion slices, and lemon juice. Enjoy! :)