Caviar Puff-Pastry Stars

1/2 pound frozen puff pastry, thawed
an egg wash made by beating together 1 large egg and 1 tsp water
1/3 cup sour cream or crème fraîche
1 ounce black caviar
3 tbsp minced fresh chives

On a floured surface roll out the puff pastry 1/8 inch thick and with a 3-inch star-shaped cutter cut out 8 pastry stars.
Transfer the stars to a lightly greased baking sheet, brush the tops with the egg wash, being careful not to let the wash drip down the sides, and bake the stars in the middle of a preheated 400°F. oven 12 to 15 minutes, or until they are puffed and golden.
Transfer the stars to a rack and let them cool completely. With a sharp small knife carefully split the stars in half horizontally to form a total of 16 stars, leaving the bottoms cut sides up and the tops cut sides down. Just before serving, spoon about 1 tsp of the sour cream onto each star, divide the caviar among the stars, and sprinkle the hors d'oeuvres with the chives.