- 1/4 cup walnuts (1 ounce), minced
- 2 teaspoons unsalted butter, melted
- 1/8 teaspoon fine sea salt
- 1 sheet frozen puff pastry (from a 17 1/4-ounce package), thawed
- 1 large egg, lightly beaten with 1 tablespoon water
- 6 ounce Camembert (not runny), rind discarded
- 1/3 cup walnuts (1 1/4 ounce), finely chopped, toasted , and cooled
- Special equipment: a 1 1/2-inch round cookie cutter; parchment paper
- Preheat oven to 400°F.
- Stir together walnuts, butter, and salt.
- Roll out pastry on a lightly floured surface with a lightly floured rolling pin into a 14- by 12-inch rectangle. Cut out 40 rounds with lightly floured cookie cutter and discard trimmings.
- Brush tops of rounds with egg wash, then sprinkle each with about 1/4 teaspoon walnut mixture and transfer to a parchment-lined large baking sheet. Bake rounds in middle of oven until golden and puffed, 10 to 15 minutes, then slide pastries on parchment onto a rack to cool. (Leave oven on.)
- While pastries are still warm, gently pull each one apart to make a top and a bottom. Lightly press down any puffed inner layers on tops and bottoms if necessary.
- Mash together cheese and toasted walnuts with a fork.
- Sandwich a 1/2-teaspoon mound of cheese filling inside each pastry (between top and bottom), then bake in middle of oven on parchment-lined baking sheet (it's not necessary to use a clean sheet of parchment) until cheese begins to melt, 2 to 3 minutes. Season tops of pastries with pepper and serve immediately.