Heat the oil in a large Dutch Oven over medium high heat. Add in the carrots, celery, and onion. Saute for 3-4 minutes.

Add in the chicken and cook for about 5 minutes, stirring frequently, or until the chicken is no longer pink.

Add in the garlic and saute for 1 minute.

Pour the chicken broth into the Dutch oven and bring the soup to a boil. Add the orzo and cook, uncovered, for 6-7 minutes.

In a medium bowl whisk together the eggs and lemon juice.

Remove 1 cup of the boiling soup from the pot. Slowly add the hot soup to the egg mixture,, whisking constantly, to temper the eggs.

Pour the egg mixture into the Dutch oven and stir to combine.

Reduce the heat to medium and stir in the spinach, salt, pepper, and oregano.

Serve hot.