Spray 6 quart slow cooker with cooking spray. Layer in carrots, potatoes, mushrooms, onions, and meatballs.
In a medium bowl, stir together undiluted soup, undrained tomatoes, thyme, and beef broth. Pour over meatballs. Cover and cook on low 8-10 hours. Stir gently before serving. Garnish with fresh parsley.
Substitute Beefy Mushroom soup for the Golden Mushroom.