Heat the olive oil in a large soup pot over medium heat. Add the onion, carrots, and celery, and cook for about 5 minutes, until the onion turns translucent.
Stir in the garlic and cook for 30 seconds, until fragrant.
Nestle the chicken into the pot and sear briefly on each side.
Pour in the chicken broth, then add the bay leaves and thyme. Bring to a gentle boil, then reduce the heat and simmer, partially covered, for 25-30 minutes, until the chicken is fully cooked through.
Remove the chicken with tongs and let it cool slightly. Shred the meat with two forks, discarding the skin and bones, and return the shredded chicken to the pot.
Add the egg noodles and simmer for 6-8 minutes, until just tender.
Stir in the lemon juice, then season with salt and pepper to taste.
Ladle into bowls and top with fresh parsley before serving.