Heat the olive oil in a large pot over medium heat. Add the onion, carrots, and celery and cook for 5 minutes until the vegetables begin to soften.
Stir in the garlic and ginger and cook for 1 minute until fragrant.
Pour in the chicken broth and add the chicken breasts. Bring the mixture to a simmer and cook for 15 minutes until the chicken is cooked through.
Remove the chicken from the pot, shred it with two forks, and return it to the broth.
Add the orzo and cook for 8 to 10 minutes until tender.
Stir in the lemon juice and spinach. Cook for 2 minutes until the spinach wilts. Season with salt and pepper.
Ladle into bowls and top with chopped parsley before serving.