In a large saucepan, bring the broth to a boil. Add the orzo and cook until tender but still al dente (the Italian term for “not mushy”), about 7 minutes. Season to taste with salt and pepper and reduce heat to low.
Simmer while prepping the rest of the ingredients.
In a large measuring cup, whisk together the eggs and lemon juice until smooth. I like using a measuring cup, because it makes it easier to add the mixture to the orzo.
This next step is really important in order to avoid a scrambled egg soup! Ladle about 1 cup of the hot broth into the egg-lemon mixture and whisk to combine.
The fancy cooking term for this is tempering. Tempering brings the egg-lemon mixture to the same temperature as the broth. If you add this mixture directly to the broth without tempering you’ll wind up with scrambled eggs. Not exactly the result you’re going for with this recipe.
Pour the tempered egg-lemon mixture back to the simmering saucepan, and whisk to incorporate. Once it’s incorporated, stir constantly until the soup thickens and the eggs cook, about 2 minutes. Add the chicken, and season to taste with salt and pepper.
Ladle finished soup into bowls and garnish with an extra few drops of lemon juice and parsley.