The “modern” in Fiesta! Modern Mexican Cuisine refers to the décor, not the food. Rather than run with the all-too-popular sombrero-laden faux-cantina template, this Chesterfield restaurant has opted for a clean, contemporary look. The lengthy menu, though, features mucho gringo-friendly fare: burritos, enchiladas, quesadillas, fajitas and chimichangas. Best bets tend to fall under the “Chef Special” heading, including tacos al pastor, generous servings of pork with pineapple and chopped onion and cilantro with a fiendishly hot salsa. The “Fiesta Soup,” with steak, strips of nopal cactus, bacon and beans in a thin but deeply flavored broth, is a welcome change of pace.