Place the onion and ginger on a grill tray and place under a hot grill to char on all sides. The onion should be soft and slightly caramalised.
Remove from the grill and add to a pot with the chicken and toasted cloves, star anise and coriander seeds.
Cover with cold water and bring to the boil.
Simmer for 50 minutes or until the chicken is cooked all the way through. Remove the chicken and set aside to cool before removing the skin and shredding the meat.
Add the fish sauce, bring the remaining liquid back to the boil and then lower the heat and simmer for a further 40 minutes until the flavour has intensified. Season with sea salt to taste.
Strain the broth through a fine sieve and skim any fat from the top once it settles.
Place the broth back in the pot and bring to the boil. Add the rice noodles and cook until soft.
Serve the noodles and broth in deep bowls and top with the shredded chicken, mint leaves, basil leaves, coriander leaves, red onions, spring onion and a wedge of lime.
Slurping is a completely necessary part of devouring this soup.