Sauté the Vegetables:
In a large pot, heat olive oil over medium heat. Add the onion, carrots, and celery. Cook for about 5 minutes until softened. Add the garlic and sauté for another minute.
Add Chicken and Broth:
Place the chicken breasts into the pot. Pour in the chicken broth and add the thyme, bay leaf, salt, and pepper. Bring to a gentle boil, then reduce heat and simmer for 20 minutes.
Cook the Orzo:
Remove the chicken from the pot and set it aside. Stir in the orzo and let it cook for 8-10 minutes, stirring occasionally to prevent sticking.
Shred the Chicken:
While the orzo cooks, shred the chicken using two forks. Return the shredded chicken to the pot.
Add Lemon Juice:
Remove the bay leaf and thyme sprigs. Stir in the freshly squeezed lemon juice and taste.
Adjust the seasoning if needed.
Serve:
Ladle the soup into bowls and garnish with parsley and grated Parmesan if desired. Serve hot and enjoy!