Beef heart kabobs. They were awesome. Can't cook em much past rare, but they taste extremely beefy but just a touch of organ flavor. Make sure put the veggies on one skewer and the meat on another since the veggies take a lot longer to cook.
Crisped up some beef tongue slices one time too on my Weber that I had already braised till tender in the oven. Made for a great sandwich. Shredding it is good on a sandwich too.
My next weird thing is gonna be pork brains. Can't figure out what to do with them on the grill or smoker, but I saw them in the frozen meat section at my small town grocery store and had to get them. Just too weird to pass up! I'm thinking blanch, peel, and grill with some sauce and chorizo and do tacos!
Weber Spirit E-310, Weber Performer, Weber Smokey Joe, Mini-WSM, ECB Electric.