1. Preheat oven to 375 degrees Fahrenheit. Line two baking sheets with Gefen Parchment Paper.
2. Crumble the chestnuts with your fingers, or mash with a fork, and place in a small saucepan. Add the sugar, cardamom, milk, and salt. Bring mixture to a boil and stir until the sugar has dissolved. At this point you can use an immersion blender or food processor to puree the mixture. Place the chestnut puree in another container, cover, and cool. The mixture should be a spreadable consistency, but does not have to be perfectly smooth – I like it with a bit of texture.
3. Slice the pears in half and remove the stem and core. Thinly slice the pear halves.
4. Remove the puff pastry from the package and carefully unroll. If the dough is too soft, roll it back up and place in the freezer for a few minutes. Cut the dough into approximately four-by-four-inch squares. Place about six to eight squares on the prepared baking sheet, leaving a bit of space in between.
5. With a sharp knife, carefully score a half-inch border around the edges of the square of dough, being careful not to cut all the way through.
6. Place one heaping tablespoon of the chestnut mixture and spread it in the center square of the dough, to the scored lines. Top the chestnut mixture with one teaspoon of the fruit spread.
7. Fan out three to four slices of pear on top of the chestnut and fruit spread. Then top with an additional teaspoon of fruit spread.
8. Place the pan in the middle rack of the preheated oven for 20 to 25, until puffed and golden brown. Allow to cool for five minutes and then slide the parchment paper off the tray to finish cooling.
9. Repeat with the remaining squares of dough.