Heat a large pot over medium heat then add a drizzle of olive oil. Add the shallots and cook for 4-5 minutes. Add garlic and the rest of the spices along with the fish sauce, chicken stock and chicken meat. Bring to a simmer, part cover the pot with a lid and simmer until the chicken is cooked through, about 15 minutes.
Remove cooked chicken from the cooking liquid and place on a large plate. Use 2 forks to pull the meat apart into shreds.
Place a fine mesh sieve over a large bowl and pass the cooking liquid through the sieve to remove the spices, which you can discard.
Taste cooking liquid and add salt or more fish sauce if needed. Return liquid to the pot, bring to the boil and add dried noodles. Remove from heat once noodles are just cooked.
To serve, divide noodles and soup into serving bowls. Add shredded chicken then top with spring onion, carrot ribbons and bean sprouts. Garnish each bowl with fresh coriander, crispy shallots, chilli slices and a wedge of lime. Serve immediately.
