Korean barbecue restaurants—where meals revolve around ribbons of meat sizzling on individual tabletop grills—may well be the Japanese steakhouses of the new millennium. 678, the latest entrant in the field, set up shop in spring 2012. It fuses styles by featuring pork and beef equally, and it weaves in some fresh flourishes. Start with the pork belly and either the sliced ribeye, satisfyingly straightforward, or the sirloin steak for the contrast of its marinade.