Active time: 30 min Start to finish: 50 min
For pastry
1/4 cup walnuts (1 oz), minced
2 teaspoons unsalted butter, melted
1/8 teaspoon fine sea salt
1 sheet frozen puff pastry (from a 17 1/4-oz package), thawed
1 large egg, lightly beaten with 1 tablespoon water
For cheese filling
6 oz Camembert (not runny), rind discarded
1/3 cup walnuts (1 1/4 oz), finely chopped, toasted, and cooled
Special equipment: a 1 1/2-inch round cookie cutter; parchment paper
Make pastry:
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.
Make filling while pastry bakes:
Mash together cheese and toasted walnuts with a fork.
Fill pastries:
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.
Cooks' notes:
� Puff pastry can be baked and rounds separated into tops and bottoms 1 day ahead, then cooled completely and kept at room temperature in an airtight container.
� Pastries can be filled (but not baked) 1 hour ahead and kept, loosely covered, at room temperature.
Makes 40 hors d'oeuvres or 8 servings.