Take the chicken out of the fridge 20 minutes before cooking.
Heat olive oil in a large skillet over medium-high heat. Season the chicken to taste with salt and pepper.
Add the chicken to the heated oil and cook for 5 minutes per side. Add the chicken broth and lemon wedge and cover the skillet with a lid. Cook the chicken for 10 minutes or until the internal temperature reaches 165ºF at the thickest part.
Remove the chicken from the skillet and discard the cooking liquid.
Let the chicken cool to room temperature. Then, shred it with two forks or a chicken shredder.
Prepare the soup:
Dice your veggies into evenly-sized pieces. Mince the garlic.
Heat olive oil in a large pot over medium-high heat.
Add the carrots, onion, parsnip, and celery stalk. Cook the veggies for 5 minutes, stirring. Add the minced garlic and cook until fragrant.
Rinse your rice thoroughly until the water runs clear. Then, place the rice in a fine-mesh sieve and set it aside.
Add chicken stock and bay leaf to the pot. Bring the stock to a boil. Once it boils, add rice and reduce heat. Simmer the soup for 15-20 minutes, or until the rice is tender. Stir in the cooked chicken.
Whisk the egg in a bowl with lemon juice. While whisking, gradually pour in ½ cup of the cooking/soup liquid to temper the egg.
Pour the egg mixture back into the soup and stir. Remove the soup from the heat.
Ladle the soup into a bowl. Serve garnished with chopped parsley.
Notes
This avgolemono soup is made with rice, but if you want something different, you can use Kritharaki. This small rice-shaped pasta is very popular in Greece, and you may also know it as Orzo. If you want to use this pasta instead of rice, reduce the cooking time to 8-10 minutes or according to package directions.
If you have some leftover chicken, cooked or rotisserie, you can use it in this recipe.
Once you whisk in the egg and lemon mixture, remove the soup from the heat immediately. If you leave it on the stove, the eggs and the soup may separate.
The easiest and fastest way to shred the chicken is by using a chicken shredder, but if you do not have one, you can use a stand mixer. Add the chicken into the bowl of your stand mixer. Using a paddle attachment, you can shred chicken within 15 seconds.