Nopales are a staple ingredient of Mexican cooking, yet the cactus pads are still something of a rare find on many Valley Mexican menus. Not so at Centrico, the Mexican cafe inside the historic San Carlos Hotel in downtown Phoenix. The kitchen serves up a terrific steak and nopales taco. The grilled skirt steak is chopped up into blistering nubs, topped with juicy strips of grilled cactus punched up with chipotle salsa, and served over buttery flour tortillas. It's a great taco, one that skillfully makes use of grilled nopal to add a pleasingly smoky and tart dimension to a familiar dish.