1. Heat the olive oil in a large soup pot over medium heat until shimmering.

2. Add the onion, carrots, and celery and cook until softened and lightly golden, about 4 to 5 minutes.

3. Stir in the garlic and dried thyme and cook for 30 seconds until fragrant.

4. Nestle the chicken breasts into the pot and pour in the chicken broth, then season with salt and pepper.

5. Bring to a gentle boil, reduce heat, and simmer until the chicken is cooked through, about 10 to 12 minutes.

6. Remove the chicken and shred it with two forks, then return the shredded chicken to the pot.

7. Add the orzo to the simmering broth and cook, stirring occasionally, until al dente, about 7 to 9 minutes.

8. Stir in the lemon juice, lemon zest, and chopped parsley and adjust seasoning to taste.

9. Ladle the soup into bowls and serve warm with an optional sprinkle of parsley or a lemon wedge.