See the photographs above for reference.
Preheat an oven to 400 degrees.
Line a sheet pan with parchment paper.
Roll the puff pastry sheet into a 9"x12" rectangle.
Using the lines in the puff pastry from where it was folded, cut three long strips.
Then cut each strip in half, so you should now have 6 small rectangles.
Roll each rectangle into a square. The squares should be about 6"x6"
Repeat with the remaining sheet of puff pastry.
If making the Ham & Cheese Breakfast Parcels then turn the square so that it is a diamond shape, put a slice of ham, a slice of cheese, and slice of bacon broken in half.
If doing the Prosciutto and Parmesan Parcel then put two slices of Prosciutto and 1 tbsp of Parmesan in the middle instead. I like to do half and half. 6 Ham and Cheese and 6 Prosciutto and Parm.
Fold one corner of the dough into the center. Then fold the other corner of dough to the center. It will look like it's hugging itself.
Mix the egg yolk with 1 tsp water. Brush the egg wash onto the bottom of the two corners and press the top corner into it. This way it will stay wrapped up while it's cooking.
Then brush the entire parcel with egg wash.
Bake the parcels for 20-25 minutes in a 400 degree oven. If you did not precook your bacon slightly it will take longer, about 10 additional minutes.