Coat slow cooker bowl with nonstick cooking spray. Place onion in bottom and add beef; season with salt. Add green pepper, carrots, celery and garlic. Pour tomatoes and 3/4 cup of the broth over the top.
Cover and cook on HIGH for 6 hours or LOW for 8 hours.
Mix cornstarch with remaining 1/4 cup of broth until smooth. Stir into slow cooker during last 15 minutes of cooking; add hominy.
Serve with corn tortillas and salad, if desired.