On National Grilled Cheese Sandwich Day (April 12), who better to talk to than the owner of Mars Cheese Castle in Kenosha, Wisconsin? Third-generation owner Michael Ventura tells WGN’s Steve Alexander how his grandfather, Mario, fresh out of the Navy and living in California, saw businesses popping up next to interstate highways, which Wisconsin didn’t have yet. That was 1947. Mario came home and found a spot next to what would become I-94 to start a business where all of Wisconsin’s cheeses could be featured in one store. Michael also shares the secrets to one of the Castle’s mainstays: the grilled cheese sandwich.