Place the chicken in the bottom of the crockpot.
Add the chopped onion and frozen mixed vegetables on top.
Mix the cream of chicken soup, chicken broth, garlic powder, thyme, salt, and pepper in a bowl.
Pour the mixture over the chicken and vegetables.
Cover and cook on low for 6 to 8 hours.
About 30 minutes before serving, add the egg noodles.
Stir to combine and cover again.
Check the chicken for tenderness and shred if necessary.
Serve hot and garnish with fresh parsley.