Stick cloves in onion. Place onion and beef in slow cooker and add enough water to cover ingredients plus 3 more inches. Cover and cook on LOW for 5 hours.
Add carrots, potatoes, onions and cabbage to slow cooker and cook an additional 3 hours.
Remove corned beef from slow cooker and slice. Place on large platter with vegetables. Drizzle with the broth to moisten and serve.