Heat the olive oil in a medium pot over medium heat until shimmering.
Add the diced onion, carrots, and celery to the pot and sauté for 5 to 7 minutes until the vegetables are softened and the onions are translucent.
Stir in the minced garlic and cook for 1 minute until fragrant but not browned.
Pour in the chicken broth and bring the liquid to a gentle simmer.
Place the whole chicken breast into the simmering broth, ensuring it is fully submerged, and cook for 12 to 15 minutes until the internal temperature reaches 165 degrees Fahrenheit.
Remove the chicken from the pot and use two forks to shred it into bite-sized pieces.
Return the shredded chicken to the pot and season the soup with sea salt and black pepper.
Stir in the freshly chopped parsley and serve warm in a large bowl.