In a large pot, heat a splash of olive oil over medium heat. Add the chopped onion and sauté until translucent (about 5 minutes).
Add the minced garlic, diced carrots, and celery to the pot, stirring occasionally for another 3-4 minutes until the vegetables are slightly tender.
Pour in the chicken broth and bring the mixture to a boil.
Once boiling, add the chicken breasts, orzo pasta, dried oregano, salt, and pepper. Cover and let it simmer for 15-20 minutes, or until the chicken is cooked through.
Remove the chicken from the pot and shred it using two forks. Return the shredded chicken to the soup.
In a separate bowl, whisk the eggs. Slowly temper the eggs by adding a ladle of the hot soup into the bowl while whisking continuously (this prevents the eggs from curdling).
Gradually stir the tempered egg mixture back into the soup, adding the lemon juice and zest. Stir well to combine.
Adjust seasoning with more salt and pepper if necessary. Allow the soup to heat through for another 2-3 minutes, but do not let it boil.
Serve hot, garnished with chopped fresh parsley for added flavor and color.
Notes
Serve hot and garnish with fresh parsley for added flavor.