Heat oil in a large pan over high heat. Char onion and ginger by placing facedown and leave undisturbed for 2 minutes until they blacken. Turn and leave for another 2 minutes.
Add water and all other ingredients except salt under “Soup broth” to the pan. Heat the pan until it simmers and then lower the heat, until it’s simmering very gently with the lid on.
Simmer for 1.5 hours. Remove the chicken, then strain broth into a clean pot. In the end you should have 750 ml water left, top it up if you have less or simmer to reduce.
Add salt, then turn the heat off once it simmers.
Shred chicken meat from the bones, you can use two forks to do that. The traditional Pho Ga should have the chicken skin removed, but as I like it, I left them on.
Prepare noodles per packet direction right before serving and drain the excess water very well.
Place noodle in bowls, top it up with chicken and add the toppings, add a squeeze of lime into the broth and sauce to your own preference.