Begin by heating olive oil in your chosen cooking vessel over medium heat. Add diced celery, carrots, and finely chopped onions, sautéing them until they soften and become fragrant.
Next, add the boneless, skinless chicken breasts into the pot with the sautéed vegetables. Allow them to cook until they are no longer pink on the outside, ensuring that they are just starting to brown slightly.
Now it's time to stir in minced garlic along with both sizes of Yukon gold potatoes, salt, black pepper, dried parsley, basil, rosemary, and chicken broth. Mix everything well to combine the flavors before bringing it to a gentle simmer.
Cover your pot and let it simmer on low heat for about 30 minutes or until the chicken is fully cooked through and tender enough to shred easily with forks.
For a creamier texture reminiscent of traditional pot pie filling, consider blending half of your soup using an immersion blender or transferring it in batches to a countertop blender before returning it back to the pot.
Stir in your choice of milk and garnish with fresh parsley before serving warm in bowls for that ultimate comfort experience!