The California-based taco chain Del Taco is celebrating its 50th anniversary by launching a "Throwback Menu." On this historic menu is the "Bun Taco." It's basically what would normally go inside a taco (seasoned beef, cheddar cheese, lettuce, and tomato) but it all gets crammed inside a sesame seed bun. Apparently it's been part of the "secret" menu for a while (it was inherited from the Naugles chain). Is it a taco meat sandwich? A taco burger?