- 2 sheets puff pastry , defrosted and rolled into 10-inch squares
- 1 tablespoon Dijon mustard (Smooth or grainy, your preference)
- 6 ounces shredded Emmental swiss cheese
- 4 ounces thinly-sliced ham (I use Black Forest or Virginia)
- 1/3 cup caramelized onions
- 1 teaspoon chopped thyme leaves
- 1 large egg
- 1 tablespoon milk
- 1/4 teaspoon garlic powder
- 1 tablespoon chopped fresh parsley
- Preheat oven to 400 degrees F. Line a baking sheet with parchment paper.
- Place one piece of puff pastry onto the baking sheet and spread with mustard, leaving a 1/2-inch border.
- Sprinkle half of the shredded cheese over the mustard. Layer ham slices over the cheese, followed by the caramelized onions, thyme, and remaining cheese.
- In a small bowl, whisk together egg, milk, garlic powder, and parsley.
- Lightly brush the border of the puff pastry with the egg wash. Place the second square of puff pastry over the top and press the edges to seal.
- Brush a 1/2-inch border on the top sheet of puff pastry with egg wash. Fold bottom edge of puff pastry over to create a crust of double thickness. Crimp edges with a fork.
- Brush top of puff pastry with egg mixture (you won’t use the entire amount). Cut three, 1- to 2-inch slits in the center of the pie to allow steam to escape while baking.
- Bake for 25 minutes, until puffed and golden. Let stand for 10 minutes before slicing into squares or strips and serving.