In a large pot or Dutch oven, melt butter over medium heat. Add onion, carrots, and celery, cooking for 5-7 minutes until vegetables begin to soften.
Add minced garlic and cook for another minute until fragrant, stirring constantly to prevent burning.
Pour in the chicken broth and add thyme, bay leaf, salt, and pepper. Bring to a boil.
Add the egg noodles and reduce heat to medium. Cook for 8-10 minutes until noodles are tender.
Stir in the cooked chicken and heat through for 2-3 minutes.
Remove bay leaf, taste and adjust seasonings as needed. Garnish with fresh parsley if desired and serve hot.