Creamy Greek Lemon Chicken Soup (Avgolemono)

Heat olive oil in a large soup pot over medium heat. Add diced onion, celery, and carrots. Sauté for 8–10 minutes, stirring occasionally, until vegetables are soft and fragrant.
Add minced garlic and bay leaves to the pot. Sauté for 30 seconds until fragrant (do not let garlic brown).
Pour in the chicken broth. Bring to a gentle boil.
Stir in the uncooked rice or orzo. Reduce heat to a simmer and cook, stirring occasionally, until rice is tender but not mushy, about 20–30 minutes.
Add shredded cooked chicken and simmer just until warmed through, about 3–5 minutes.
While the soup simmers, whisk the egg yolks with lemon juice in a medium bowl until pale and frothy.
Slowly ladle about 2 cups of hot broth from the soup into the egg-lemon mixture in a thin stream, whisking constantly to temper the eggs.
Turn off the heat under the soup. Gradually pour the tempered egg-lemon mixture back into the pot, stirring gently.
Remove and discard bay leaves. Taste and season with salt and black pepper as desired. Ladle into bowls, garnish with chopped dill or parsley, and serve.