Five years ago, chef/owner Richard Sandoval's Tamayo was on the cutting edge of the Nuevo Latino culinary movement, with critics in Denver and beyond raving about the pipian de puerco (tamarind-marinated pork tenderloin in a pumpkin-seed sauce), the ceviche (mahi mahi in a spicy tomato broth) and the crepas de cajeta served at his Larimer Square outpost. But while the culinary world has moved on, Tamayo is stuck in time. The pipian de puerco, the crepes and ceviche are all still on the menu, essentially unchanged from that day in 2001 when Tamayo made its best and biggest splash. Mexican food -- even "Modern Mexican," a catchphrase that Sandoval more or less invented -- has evolved considerably over half a decade, but Tamayo has stubbornly refused to evolve along with it. True, there's still some mileage left in the open-faced shrimp quesadillas served like an explosion at a guacamole factory, and in the arrachera with rare skirt steak served over a rajas gratin -- but that's mostly because these Modern Mexican preparations were so wildly new back then that it's taken several years for the rest of the gourmet world to catch up. Sandoval is near-legendary for keeping a tight control over the menus he writes, for not allowing his cooks and chefs to change anything, keeping every preparation as pure as a mathematical formula. And while this has worked for him for a long time, it can't keep working forever. Innovation is what keeps restaurants fresh, and though Tamayo still looks good and continues to make some nice moves (the crepas with cajeta are a great way to finish any meal), its Modern Mexican act is starting to look -- and taste -- a little stale.