Put the dried rice noodles into a large bowl, cover with boiling water and allow to stand for 20 minutes or until just soft, drain well. The hot broth will soften them when it is poured over at the end.
Meanwhile, Put the consommé into a large pan with 2 cups (500ml) water, add the cinnamon, star anise, ginger, fish sauce and sugar and bring to boil, reduce heat and simmer uncovered for 20 minutes. Strain and return the broth to the pan, discard the spices.
Put the soup back onto the heat and bring to boil. Add the shallots and thinly sliced beef, mushrooms and bok choy to the broth and simmer for 5 minutes or until the beef is just cooked.
Divide the noodles and sprouts between four large soup bowls, Top with the boiling soup broth. Finish with some extra beans sprouts, a squeeze of lemon, coriander leaves and cracked black pepper.