- 1 package (2 sheets) frozen puff pastry, defrosted*
- 2 tablespoons Dijon mustard
- ¼ pound black forest ham, thinly sliced
- ½ pound Gruyère cheese, grated
- 1 egg
- flour for dusting
*Defrost overnight in the fridge before you begin.
**Puff pastry sheets are available in the frozen section of most grocery stores. If you cannot find them, you can use a whole block of dough instead. On a lightly floured work surface, roll out the dough and cut it into two sheets measuring approximately 10 x 12 inches (use a ruler if necessary). Transfer to a piece of parchment paper and proceed with the rest of the recipe.
- Preheat your oven to 450 F.
- To make the egg wash, lightly beat an egg with 1 tbsp. of water. Set aside.
- Place a piece of parchment paper onto your work surface and dust lightly with flour.
- Lay one sheet of puff pastry on top of the paper.
- Using the back of a teaspoon, brush the dough with mustard leaving a 1-inch border around the edge. Use a ruler if necessary.
- Staying within the border, add the sliced ham in overlapping layers.
- Add the cheese.
- Brush the border with some of the egg wash to create a seal.
- Place the second sheet of puff pastry on top of the filled pastry lining up the edges.
- Using a sharp knife, trim the dough so that the edges line up and the square is even. It’s just like cutting the crust off of a sandwich. Make sure to cut the dough in a swift downward motion (think paper slicer). If you drag your knife, it will not rise properly. Press down lightly.
- Brush the top with more egg wash and cut a few slits in the top to allow steam to escape.
- Transfer the dough to a baking sheet by lifting up the parchment paper.
- Bake for 20 to 25 minutes, until puffed and golden brown.
- Allow to cool for a few minutes and cut into squares (about 12-16 depending how large you want them).
- Serve hot.