Mushroom, Rajas, and Corn Taco with Queso Fresco

The earliest Mexican cuisine was vegetable-based, so in times past, before Spanish beef, chicken, and pork worked their way into every taco, there were no doubt plenty of satisfying vegetable taco recipes. Today most vegetables are consumed as salsas, in soups, or stuffed into quesadillas and empanadas, but there’s no reason why a vegetable taco shouldn’t be every bit as tasty and unusual as any other. This sumptuous vegetarian feast is based on the classic combination of roasted poblano ch