Begin by preparing your fresh ingredients: dice celery, carrots, and onion; mince garlic; and cut Yukon Gold potatoes into both small and large pieces.

In your Instant Pot, heat olive oil on sauté mode. Add chicken breasts and sear for about 2 minutes on each side until golden brown.

Remove the chicken from the pot, then add the diced celery, carrots, onion, and minced garlic. Sauté for approximately 2 minutes.

Layer the cooked chicken back into the pot along with small potato pieces. Arrange larger potato quarters on top.

Pour in the chicken broth and seal the lid. Cook on high pressure for 9 minutes.

Let the pressure naturally release for 5 minutes, then release any remaining pressure manually.

Remove large potato pieces and chicken from the pot. Blend the potato quarters with milk and some broth until smooth.

Shred the chicken and return it to the pot with the blended mixture. Stir until combined.

Ladle soup into bowls, garnish with fresh parsley, and serve hot.