Prep the beef: Pat the beef dry and season generously with salt and pepper.
Dry meat sears better and builds more flavor.
Sear for depth: Heat olive oil in a skillet over medium-high. Sear the beef in batches until browned on at least two sides. Don’t overcrowd the pan.
Deglaze the pan: Add a splash of broth to the hot pan and scrape up the browned bits.
Pour this liquid into the slow cooker for extra flavor.
Load the slow cooker: Add onion, carrots, celery, garlic, barley, tomato paste, Worcestershire, bay leaves, thyme, rosemary, and smoked paprika.
Add broth and beef: Pour in the remaining broth and the seared beef. Stir to distribute the tomato paste.
Set and cook: Cover and cook on Low for 7–8 hours or High for 4–5 hours. The beef should be tender and the barley fully cooked.
Taste and adjust: Remove bay leaves.
Taste and season with more salt and pepper as needed. If the soup is thicker than you like, add a cup of hot water or broth.
Garnish and serve: Ladle into bowls and top with chopped parsley. Serve with crusty bread if you like.