Chicken: I typically use pulled and shredded rotisserie chicken. You can also use raw chicken breasts or thighs, add them to the pot with the simmering broth, and let them cook for about 10-12 minutes or until 165 degrees. Remove, shred, and return to pot. This would also work great with leftover Thanksgiving turkey!
Olive oil: The extra olive oil that gets added in Step 3 is there to make it taste a little extra luscious. Without it, there isn’t a lot of fat in this soup – it’s just broth and veggies and chicken. And adding a good fat to this soup, I think, helps it really go from “brothy boring soup” to “wow, that’s really good soup”. That said, the extra oil is not necessary if you’re using a homemade broth, which typically already has a nice silky feel to it because of the fat content.
Instant Pot: I have made this in my Instant Pot and it’s great. I sautéed everything as directed in steps 1-2, then for step 3 I set it to high pressure for about 3 minutes and let it natural pressure release. (If you add raw chicken to the soup, you’ll need to cook at high pressure for 10-12 minutes.)