What would you toss in a crock pot/slow cooker with a corned beef brisket?

I just made corned beef brisket yesterday! I put in about 2 potatoes, quarted, a large quarted red onion, a lot of minced garlic, a handful of bay leaves, a light beer, and about 6 cups of water. Cooked it on high for 9 hours. It was so tender and delicious. My hubby got a corned beef sandwich for lunch, and the little bit of leftover brisket is being turned into hash for tonight.