Slow Cooker Ham and Bean Soup

dry Great Northern or navy beans

Water (enough to cover dry beans by 2" for overnight soak)

diced white or yellow onion

to 3 carrots (peeled and chopped)

stalks celery (chopped)

minced garlic

dried thyme

dry mustard

salt (plus additional if desired (taste and season after cooking))

freshly ground black pepper

meaty ham bone ((trimmed of excess fat and rinsed of any glaze))

to 6 cups low sodium chicken broth (as needed)

bay leaves

tomato sauce

Fresh Italian (flat-leaf parsley, for garnish (optional))