Chop the onion. Cube the potato after washing the skin (leave skin on). Chop the carrot and celery, as well as the bell pepper.

Add all ingredients to slow cooker. Cook on low 7-8 hours or high 3-4 hours or until barley is tender.

Discard bay leaf, season with salt and pepper to taste, and consider garnishing with parmesan cheese and/or parsley.