SEASON chicken inside and out with 2 teaspoons kosher salt and ¼ teaspoon pepper, then tuck the wings behind the back.
ADD 2 tablespoons of ghee or avocado to the pressure cooker, and hit the “sauté” function on your Instant Pot. Once the fat is hot, give the pot a swirl to coat the bottom and sear the chicken breast-side down in the center of the pot for 5 minutes or until skin is golden and slightly crispy. (And no worries if the skin sticks or tears! This is just a trick to deepen the overall flavor of the soup. (Hat-tip to Nom Nom Paleo for this!)
FLIP your chicken and cook for another 5 minutes.
TRANSFER chicken to a plate and toss in the chopped onions, celery, carrots, garlic cloves, and a sprinkle of kosher salt. Cook for 3-5 minutes or until onions are translucent.
STIR in 2 tablespoons of tomato paste and cook for about 30 seconds.
TURN OFF the sauté function and add your 2 quarts of chicken broth or stock, lemon zest, and lemon juice, scraping up any browned bits that have collected on the bottom.
ADD a steamer insert to the bottom of the Instant Pot and nest your chicken on top, breast-side up, then toss in your herb bundle.
COVER and pressure cook on high for 30 minutes.
TURN OFF your Instant Pot and immediately release the pressure manually. Open the lid, toss the herb bundle, and transfer the chicken to a plate or carving board and allow to cool enough to remove the skin and shred the meat. Make sure to discard the skin, but I highly recommend saving the rest to make homemade bone broth!
ADD shredded chicken back to the pot and give everything a stir.
SEASON with additional salt and pepper, if desired.
ENJOY within 3-4 days, or freeze leftovers.