For the Marinade ẵ cup soy sauce ẳ cup honey ẳ cup Dijon mustard 2 medium cloves garlic, minced or grated on a Microplane (about 2 teaspoons) ẵ cup vegetable oil Kosher salt and freshly ground black pepper 2 pounds flap meat To make the marinade: Combine the soy sauce, honey, mustard, and garlic in a medium bowl and whisk, then slowly add the oil, whisking constantly Transfer half of the marinade to a small container and reserve Place the meat a gallon-sized zipper-lock freezer bag, add the remaining marinade, press out the air, and seal the bag Allow the meat to marinate in the refrigerator, turning occasionally, for at least 1 hour, and up to 12 hours Remove the meat from the marinade and pat dry with paper towels Ignite a large chimneyful of coals and wait until they’re covered in gray ash, then spread evenly over one half of the grill grate Put the cooking grate in place, cover, and allow the grill to preheat for 5 minutes Or, if using a gas grill, heat one set of burners to high heat and leave the rest off Scrape the cooking grates clean Place the meat on the hot side of the grill and cook until well charred on the first side, about minutes Flip the meat and continue to cook until the second side is well charred, about 3 minutes longer Transfer the meat to the cooler side of the grill, cover, and cook until the center of the meat registers 125°F for medium-rare, or 135°F for medium, on an instant-read thermometer, about minutes longer Transfer to a cutting board, tent with foil, and allow to rest for at least 5 minutes Thinly slice the meat against the grain, drizzle with the reserved marinade, and serve ...cooler side of the grill, cover, and cook until the center of the meat registers 125°F for medium-rare, or 135°F for medium, on an instant-read thermometer, about minutes longer... Transfer to a cutting board, tent with foil, and allow to rest for at least 5 minutes Thinly slice the meat against the grain, drizzle with the reserved marinade, and serve