Defrost the puff pastry sheets. Place the slices of dough on top of each other and roll out on a floured work surface to form a large sheet (approx. 3 mm thick). Cut out 24 hearts (approx. 7 cm Ø).
Wash herbs. Chop parsley finely, cut chives into fine rolls. Mix cream cheese and milk and add the herbs. Spread the cheese cream over 12 hearts, leaving an edge free.
Separate the egg. Spread the edges of the dough with egg white and place the remaining hearts on top. Press the edges of the dough firmly with a fork. Whisk the egg yolk with some water and brush the hearts with it. Sprinkle with almonds, sesame or caraway seeds.
Place the hearts on a baking tray lined with baking paper and bake in a preheated oven (electric: 200 °C/ gas: level 3) for approx. 15 minutes. Makes 12 pieces.