Original in every sense, downtown theater troupe Banana Bag & Bodice's freewheeling cabaret scrutinizes mankind's carnivorous habits through Christmas food traditions. Reveling in a DIY, rough-around-the-edges aesthetic, the show begins with a BLT sandwich being made onstage and progresses through less literal — and increasingly absurd — musical vignettes that ponder the morality of what we eat. A Very Sandwich Christmas delivers an experimental performance that parallels Eating Animals, Jonathan Safran Foer's new treatise on vegetarianism, but its ribald humor and gory kitsch make for a less serious introspection.