Heat the olive oil over medium heat in a medium size dutch oven or soup pot.
Add the onion, carrots, celery and bay leaf and stir to combine with the oil. Cook for about 7 minutes until the onion becomes translucent.
Add the garlic and salt and pepper to the vegetable mixture and stir while cooking for another minute.
Add the broth and over medium-high heat bring the soup to a low boil.
Stir in the lemon zest, lemon juice, chicken and orzo and cook for another 10 minutes. Remove the bay leaf.
Stir in the spinach right before serving.
Serve with grated parmesan sprinkled on top and extra lemon wedges on the side. Enjoy!