How to Make It
Heat oven to 400° F. Line a baking sheet with parchment.
Unfold the pastry and brush with the egg. Sprinkle with the scallions, ¼ cup of the Parmesan, ¼ teaspoon salt, and ⅛ teaspoon pepper. Roll tightly into a log. Freeze until firm but still sliceable, about 20 minutes.
Slice the log into ¼-inch-thick rounds and place on the prepared baking sheet. Sprinkle with the remaining 2 tablespoons of Parmesan and bake until golden brown, 12 to 15 minutes. Serve warm or at room temperature.