In a skillet, brown the ground beef with the chopped onion and garlic. Drain excess fat and transfer to the crockpot.
Add beef broth, potatoes, carrots, celery, Worcestershire sauce, and parsley to the crockpot.
Season with salt and pepper to taste.
Cover and cook on low for 6-8 hours or high for 3-4 hours, until the vegetables are tender.
About 30 minutes before serving, stir in the milk and cheddar cheese until melted and smooth.
Serve hot and enjoy your comforting cheeseburger soup!