Preparation To make the chicken hearts: Butterfly the chicken hearts by slicing them lengthwise, cutting deeply without cutting them entirely in half. Smash the green onions and ginger with clean hands to release their flavors. Add the smashed green onions and ginger, along with the Sichuan peppercorns, five-spice powder, cooking wine, and salt to a container along with 1 cup (240 ml) water to make a marinade. Add the chicken hearts to the marinade and stir well to combine. Cover the container with plastic wrap and let marinate in the refrigerator for 1 hour. Any longer and you risk over-marinating. To grill and serve: Thread 5 chicken hearts onto each skewer. The skewers may be kept refrigerated, covered, before cooking for no longer than 2 hours. Prepare a robata or other grill with charcoal that has turned ashy gray and is smoldering hot but not actively emitting flames. Set the skewers down on the grill surface and cook for 2 minutes, then flip over and cook for an additional 2 minutes. When the meat tightens up and oil begins to seep out, it is almost done. At this point, brush the oil on one side of the meat, then sprinkle half of the cumin, red chili powder, and salt, to taste, on top. Flip the skewers over and season the other side in the same way. Flip the skewers once more and toast the newly seasoned side for about 30 seconds. Cook for about a minute or so more on each side. Remove the cooked skewers to a plate, sprinkle with the sesame seeds, and serve immediately. Note: When brushing oil and sauce on the meat while over the fire, do so sparingly, dabbing off any excess, so it doesn’t drip onto the flames. If at any point the flames flare up, remove the skewers from the grill until the flames die down. Excerpted from Xi'an Famous Foods: The Cuisine of Western China, from New York's Favorite Noodle Shop by Jason Wang with Jessica Chou, copyright © 2020. Published by Harry N. Abrams.Buy the full book from Amazon or Bookshop.