Combine water, peas, ham steak, ham hock, and bay leaves in slow cooker. Microwave onions, celery, carrots, butter and spices until onions are soft, about 5 minutes. Transfer to slow cooker. Cover and cook until peas are tender, 8 - 9 hours on low or 5 - 6 hours on high.
Cut meat from bone and ham steak into bite size pieces. Puree soup to nice consistency.