These sticks make a delicious start to any festive meal.
Heat the oven to 425 degrees . Line two baking sheets with parchment paper. Dust a clean work surface with flour, and roll each piece of puff pastry into a 10-by-14-inch rectangle, less than 1/8 inch thick. Transfer the rolled-out dough to baking sheets; refrigerate for 15 minutes.
Remove dough from refrigerator, and generously brush one puff-pastry sheet with egg yolk. Sprinkle the salt and pepper over the sheet, then cover with poppy seeds. Brush the second pastry sheet with egg yolk, and place on top of first, yolk sides together. Gently press the two sheets together so the poppy seeds stick between them. Return the pastry to refrigerator, and chill another 15 minutes.
Remove the pastry from the refrigerator, and brush the top generously with the remaining egg yolk. Using a pizza wheel or a long sharp knife, cut the dough into 10-inch-long strips that are 1/4 inch wide. Hold a piece of dough in the middle, and start twisting in the direction of each end; twist until entire piece of dough is tightly coiled. Transfer twist to a baking pan; press the ends to metal. Repeat with the remaining dough.
Bake until the sticks are golden brown, about 8 minutes. Transfer to a wire rack to cool completely, and store in an airtight container up to 1 week.
The dough for these sticks is easiest to shape when its firm. If your pastry becomes too soft, place it in freezer until it has hardened again.