In a large pot or Dutch oven, heat the olive oil over medium heat. Add the chopped onion, diced carrots, and diced celery. Cook until the vegetables are softened, about 5 minutes.
Add the minced garlic to the pot and cook for an additional 1 minute, until fragrant.
Pour in the chicken broth and bring the mixture to a boil. Once boiling, reduce the heat to low and let the soup simmer for about 10 minutes.
Add the cooked chicken, uncooked egg noodles, and dried thyme to the pot. Stir well to combine.
Continue to simmer the soup for about 10-12 minutes, or until the noodles are tender and the chicken is heated through.
Season the soup with salt and pepper to taste, adjusting as needed.
Ladle the Homemade Chicken Noodle Soup into bowls and garnish with fresh parsley, if desired.
Serve the soup hot and enjoy the comforting flavors of this homemade classic!