Melt the chocolate square. Bring water, chicken and celery to boil. Cover and reduce heat, letting simmer about 1 hour, or until meat comes away easily from bones. Remove chicken from broth and set aside to cool. Strain broth and keep liquid; discard celery. In a blender, combine half of broth with six seasonings, raisins, corn chips and onion. In a large frying pan, heat oil and add blended ingredients. Heat while stirring for 5 minutes. Add remaining broth, tomato sauce and melted chocolate to frying pan. Cover pan and simmer on low heat 20 minutes. Meanwhile, cut chicken into pieces; add to sauce in frying pan. Salt if desired. Cook everything together 10 minutes. Toast almond slivers and use as garnish. Serve with brown rice, steamed corn tortillas, and a green salad. Serves 6.