Place ingredients (except oil and barley) into slow cooker. Cook on low for 10 hours. Stir in barley during the last hour of cooking. Once the barley is tender, season to taste with salt and pepper and serve.
Heat a large soup pot over medium-high heat then add oil. Once oil is hot, add beef stew meat then cook for about 5–6 minutes until browned on all sides. Add onion, carrots, celery and garlic then stir to coat veggies in oil. Cook veggies for 5–6 minutes until they begin to soften and the onions are translucent.
Pour in wine (if using) then beef stock and diced tomatoes with juice, bay leaf, basil, oregano, beef bouillon and Worcestershire sauce. Stir to combine then bring to a boil. Once the liquid begins to boil, reduce heat to low, cover then simmer for 1½ hours, stirring occasionally.
After 1½ hours, add barley then stir to combine. Return the lid and continue simmering the soup for 1 additional hour, stirring occasionally.
Once the barley is tender, remove soup from the heat, season to taste using salt and pepper then serve nice and hot. Enjoy!
One Last Thing
Serve this stew with a loaf of rustic bread. It’s perfect for dipping!