Slow Cooker Beef Barley Soup

INGREDIENTS

• 1 1/2 pounds boneless lean beef, cubed
• 3 tablespoons vegetable oil
• 1 teaspoon salt
• 1 teaspoon ground black pepper
• 2 teaspoons garlic powder
• 3 (10.5 ounce) cans beef broth
• 6 cups water
• 4 stalks celery, chopped
• 6 carrots, chopped
• 6 green onions, chopped
• 1/2 cup chopped fresh parsley
• 1 cup barley
• 1 teaspoon dried thyme