Brown the Beef: In a non-stick skillet, brown the beef pieces over medium heat, stirring frequently. Remove and transfer to the crock-pot.
Combine Vegetables and Broth: Add carrots, celery, onion, mushrooms, beef base, water, garlic, and bay leaf to the crock-pot.
Cook the Soup: Cook on high for 1 hour. Add pearl barley, then reduce heat to low. Continue cooking until beef and vegetables are tender, about 2–3 more hours.
Finish: Season with salt and pepper to taste. Discard the bay leaf before serving.
Serving and Storage Tips:
