01 - Preheat oven to 375°F. Line a baking sheet with parchment paper.
02 - Combine cream cheese, garlic, parsley, Parmesan cheese, black pepper, and salt in a mixing bowl. Stir until smooth and evenly blended.
03 - Pipe or spoon the cream cheese mixture into each mushroom cap, mounding the filling slightly.
04 - Slice puff pastry into thin strips, about 1/4 inch wide. Arrange the strips across each filled mushroom to replicate mummy bandages, leaving gaps for eyes.
05 - Brush the pastry strips with a light coating of beaten egg using a pastry brush.
06 - Position two olive slices in the exposed filling on each mushroom to create eyes.
07 - Arrange decorated mushrooms on the prepared baking sheet and bake in the preheated oven for 18 to 20 minutes, until pastry is golden and mushrooms are tender.
08 - Remove mushrooms from the oven and let them cool briefly before serving.