Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a pan, melt butter over medium heat. Scramble the eggs until just set. Remove from heat.
Roll out the puff pastry and cut into 4 equal squares.
Spoon scrambled eggs onto one half of each square, leaving space around the edges. Add ham and sprinkle with cheese.
Fold the pastry over the filling, pressing the edges with a fork to seal.
Brush the tops with egg wash (1 egg whisked with 1 tbsp milk).
Bake for 15-18 minutes or until golden brown and puffy.
Let cool slightly before enjoying!