Slow Cooker Beef Barley Soup
Heat the olive oil in a large pan over medium heat. Add the onion, celery, mushrooms and carrots. Season with the salt, pepper, and thyme. Cook until the vegetables are soft, about ten minutes. Transfer the vegetables to your slow cooker. Add the broth, bay leaves and diced tomatoes. Set the slow cooker to low and cook for three hours.
Cook the barley separately as directed on the package. Cooking the barley separately keeps it from absorbing all of the broth from your soup. Add the cooked barley to the slow cooker. After the broth has cooked for three hours add the beef. Continue to cook on low for one more hour.
Serve with warm, crusty bread.