Start by heating the olive oil in your large stockpot over medium heat. Add the diced onion and minced garlic, cooking until they become soft and fragrant, about 4-5 minutes.
Add the whole chicken pieces to the pot and pour in the 8 cups of chicken broth. Bring this to a gentle boil, then reduce the heat and let it simmer uncovered for about 45 minutes to an hour.
Once the chicken is tender, carefully remove the pieces from the pot and set them aside to cool slightly. Add the rice directly to the simmering broth and cook for about 15-20 minutes, or until the rice is fully cooked and tender.
While the rice is cooking, shred the chicken meat, discarding the skin and bones. Set the shredded chicken aside for adding back into the soup later.
In a medium bowl, whisk together the eggs and fresh lemon juice until smooth and frothy.
Slowly ladle about a cup of the hot broth into the egg-lemon mixture while whisking constantly to temper the eggs.
Slowly pour the egg mixture back into the pot with the broth and rice, stirring gently. Add the shredded chicken and chopped parsley. Let the soup heat through for a few minutes more, but do not let it boil. Taste and season with salt and pepper as needed.
Ladle the soup into bowls and garnish with extra parsley or a lemon wedge if desired. Serve warm and enjoy!