- 1 sheet frozen puff pastry (from a 17.25-ounce box), thawed
- 1 large egg, beaten
- 3 scallions, thinly sliced
- 1/4 cup plus 2 tablespoons grated Parmesan (1 1⁄2 ounces)
- kosher salt and black pepper
- 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.