In this day of Food Network stars and celebrity chefs, one culinary icon (BAM!) has been singing the praises of the pig for nearly as long as he's been mugging for the camera:   "Pork fat rules, baby".   Apparently, the man has never been to a Duck Off. Thursday night marked a unique culinary experience at Grange Restaurant: to my knowledge, Sacramento's first-ever Duck Off.  The five-course, prix fixe dinner benefitting the California Waterfowl Association, was preceded by an Iron Chef style competition between Grange executive chef Michael Tuohy and food writer Hank Shaw.  The cook-off was judged by a veritable who's-who of Sacramento Foodie Glitterati, including Darrel Corti and Rick