It seems incredible that a pig's ear can be both an excellent dog treat and a human dish of tremendous sophistication, but it's true. The cartilaginous pink flaps must first be braised or boiled to tenderness, at which point they provide a crunchy, slippery, porcine canvas for spices. But the best of the best can be found at Metro Café, a new Sichuan restaurant in Sunset Park. The cold pig's-ear appetizer is replete with ma-la flavor—the combination of tingly Sichuan peppercorns and fiery chilies—sliced into ribbons, slicked with the brick-red hot sauce, and generously sprinkled with sesame seeds, cilantro, and chopped peanuts.