How to Make It
Heat oven to 400° F. On a rimmed baking sheet, toss the grapes, oil, 1/2 teaspoon salt, and 1⁄8 teaspoon pepper. Roast, tossing occasionally, until some of the grapes begin to burst, 18 to 20 minutes.
Transfer to a bowl and toss with the ginger and sugar. Serve warm or at room temperature.