While there are probably several ways to do this, I've only experimented with one, to make spinach puffs: Slice both sheets of puff pastry into 9 equal squares. Place those in 2 lightly greased muffin trays, fill with the filling, pull the corners of the pastry to the middle and pinch together, chill for 15 minutes, then brush with the egg wash (or butter/oil) and bake for between 20-25 minutes, swapping the trays around halfway. Allow to cool for 10-15 minutes before removing the spinach puffs from the muffin tins.