Simplicity rules the day at the Charter Oak, the latest restaurant from the Restaurant at Meadowood’s Christopher Kostow. The St. Helena eatery—in the building that once housed a Napa Valley favorite, Tra Vigne—specializes in relatively simple dishes done to perfection. Exhibit A: the crudité plate, which quite literally amounts to a bowl full of freshly picked vegetables. Exhibit B: beef ribs grilled over cabernet barrels and beets dried over the fire. This is elemental cuisine. One of the restaurant’s true flourishes is that every table has a hidden drawer in which guests can find silverware, napkins, and magic that’s rare on the Napa dining scene.