Place all ingredients in the crock pot and stir. If you are using the spinach, do not add at this time. Cover and cook on low for approximately 10 hours or until beans are tender. When beans are tender, add washed spinach and cook anther minute or two.
Serve topped with some thinly grated jack cheese and some homemade croutons. (recipe for croutons is under "Healthy Soups" on this site)