Heat the olive oil in a large heavy-bottomed pot or Dutch oven over medium heat.
Add the chopped onion, carrots, and celery (the mirepoix). Sauté for 6-8 minutes until the vegetables start to soften and the onions become translucent.
Stir in the minced garlic and dried thyme, cooking for an additional 1 minute until fragrant.
Pour in the chicken broth, season with salt and black pepper, and bring the soup to a gentle boil over medium-high heat.
Once boiling, reduce the heat to a simmer. Cover the pot and let it cook for 10-15 minutes, or until the carrots and celery are completely tender.
Stir in the shredded cooked chicken and the dry egg noodles. Simmer uncovered for about 5-8 minutes, or until the noodles are cooked to your desired tenderness.
Remove the pot from the heat. Stir in the freshly chopped parsley, taste the broth to adjust the salt and pepper if necessary, and serve hot!