Heat olive oil in a large pot over medium heat.
When the olive oil is hot and begins to shimmer, add carrots, onion, celery, and garlic. Stir frequently and cook until fragrant, about 1-2 minutes.
Add chicken, bouquet garni, broth, turmeric, salt, and pepper and stir to combine. Bring the soup to a boil and lower the heat to medium-low. Cover and simmer for about 15 minutes, occasionally stirring to prevent burning.
Add orzo and cook for another 10 minutes uncovered, or until the orzo is done. Stir frequently to prevent the orzo from sticking to the bottom of the pot.
Remove the bouquet garni and discard.
Remove the chicken breast and use a food thermometer to check for an internal temperature of 165 degrees Fahrenheit. If the chicken has not reached 165 degrees, return it to the pot, simmer for another 5 minutes, and recheck it. Otherwise, shred the chicken using two forks and return it to the soup.
Stir in lemon juice and add more to taste. Garnish with fresh chopped parsley and serve.