Preheat oven to 400F.Allow puff pastry to thaw if frozen and place on a baking sheet lined with parchment.Toss nectarine slices in a bowl with ginger and brown sugar. Arrange slices on top of puff pastry, leaving about a 1 1/2 inch edge.
Brush edges of pastry with egg wash (whisk together egg and milk).Bake for 25-30 minutes, until pastry is golden and fruit is bubbly.Enjoy with whipped cream or vanilla ice cream while warm!