Press Saute on the Instant Pot and heat up the vegetable oil.
Add star anise, cloves, cinnamon, coriander, and peppercorns; cook for 3 minutes.
Stir in ginger and onion and cook for 3 more minutes.
Stir in garlic and cook for 10 seconds.
Add chicken, chicken broth, water, and fish sauce.
Cover and lock the lid.
Select “Manual” and set to cook on HIGH pressure for 18 minutes. Then, do a quick release.
Remove lid and transfer chicken to a plate. Set aside.
Strain the broth through a large mesh sieve, discarding the solids.
Return broth to the pot.
Add the noodles to the broth; cover with the lid - don’t lock it - and let sit for 3 to 4 minutes, or until noodles are tender.
In the meantime, shred the chicken, discarding the bones.
Stir chicken back into the pot.
Ladle soup into bowls.
Top with garnishes.
Serve with lime wedges.