Each of the three dining outposts of the premier oyster farmer in the Northwest has its own menu and ambience—a pregame-fried-food feel at Pioneer Square, a bright intimacy at Seattle Center, a fish market bustle at Capitol Hill—but each forefronts oysters, which you must order. Get them by the dozen or in the form of Xinh’s oyster stew, which is like slurping the nectar straight out of the shell.