This Slow-Cooker Beef Vegetable Barley Stew is the heartiest beef stew that will grace your dinner table! It's chock full of tender beef, various veggies, and barley for an extra healthy boost. Best of all, it's easily made in your Crock Pot so you don't have to babysit the stew. This recipe feeds a crowd. You can cut it in half if you wish.