After the cream cheese has come to room temperature, mix it together with the chopped chestnuts, minced onion, mustard, and parsley in a small bowl until thoroughly combined.

Preheat oven to 375°F /190°C, and very lightly grease the inside of a muffin tin.

Flatten a 10-inch sheet of puff pastry dough out on a clean, dry work surface, and allow it to thaw just until it is no longer hard and stiff (if you are working with frozen dough).

Optionally use a ridged cutter to turn each square into a fluted circle. This isn’t mandatory, but make the parties look really professional, with very little skill or effort required.

Press each portion of dough into each muffin tin cavity, slightly pressing the edges of the dough up the sides of the muffin tin.

Place about a tablespoon and a half of the filling into each pastry shell.

Evenly divide the topping into each pastry, pressing it down slightly to flatten the filling.

Bake at 375°F for 20-22 minutes until the pastry is golden brown and starting to pull away from the edges of the pan.

Allow the pastries to cool for 10 minutes. Using a butter knife or paring knife, go around the edges of each puff pastry to ensure it isn't stuck to the pan. Carefully lift each pastry out of the pan using a fork.

Serve hot, and optionally, top each pastry with a few sprigs of micro-greens of your choice.