Make the stock. You can do this either on the stove or in an Instant Pot. If doing on the stove, fill a big cast iron pot with all your stock ingredients, and then bring to a boil. Pull it down to a simmer for about 2 hours. If doing in the Instant Pot, put all ingredients in the IP, seal it, and cook at high pressure for 40 minutes. (I did a quick release, worked fine)
Strain the stock and cool the chicken. Once done, strain the stock through a fine-mesh sieve or a colander lined with cheesecloth. Put the chicken on a separate plate and cool in the fridge for at least 2 hours. Put the strained stock in a big bowl in the fridge, too, for 2 hours. After 2 hours, skim the fat off the top of the broth. Use your fingers to shred the chicken - discard the skin and bones.
To do the final soup assembly, heat oil in the same cast iron pot or put your Instant Pot on sautee mode. Wait for it to get shimmery, then throw in your aromatics. Sweat them and season with a little bit of salt. Add in the shredded chicken and broth. If doing on the stove, put the top back on and let it simmer for 40ish minutes, to let the flavors come together. If doing in an Instant Pot, seal it, and cook on high pressure for 10 minutes and do a quick release.
Optional: add in noodles if you want -- add them in near the end of the cooking time, and cook according to the package's recommended time.
Season to taste, and serve! Yum yum