(my favorite!)
Prepare the Pastry and Filling
- For the Pastry and Filling:
- 1 1/2 pounds frozen puff pastry (or 1/2 batch homemade pate feuilletée)
- 3 cups pastry cream
- 1/2 cup heavy cream, whipped to medium peaks (optional)
- For the Royal Icing and Decoration:
- 3 ounces (80 g) bittersweet chocolate, melted
- 2 large room-temperature egg whites
- 2 teaspoons lemon juice
- 3 cups (350 g) confectioners' sugar
Prepare the Pastry and Filling
- Make homemade puff pastry dough and have it ready and chilled. Or thaw store-bought frozen puff pastry dough according to the package directions.
- Make the pastry cream. Once completely cooled, you can lighten its texture if desired by folding in the optional whipped cream. Cover and refrigerate until assembly time.
- Heat the oven to 400 F (200 C).
- On a lightly floured surface, gently roll out the puff pastry dough into an elongated rectangle the thickness of a thin piece of cardboard. With a sharp knife, cut the dough into three equally-sized pieces.
- Transfer the dough to a baking pan (or pans) lined with parchment paper and pierce the dough all over with a fork.
- Cover the dough with another sheet of parchment paper and place a baking pan or pie weights on top to weigh down the dough as it bakes.
- Bake the weighed-down dough, in batches if necessary, about 25 minutes, or until the dough is deep golden brown. The weights and top layer of parchment paper pan can be removed the last 5 or so minutes of baking to help color the dough.
- Transfer the baked pastry layers to racks to cool completely.
- Set out and have everything ready -- the baked puff pastry layers, the pastry cream, and the ingredients for frosting and decorating. Don't worry if your baked pastry layers look unevenly sized. After assembly, you'll be trimming the edges for a uniform look.
- It's best to work on a flat surface for easy transfer of the finished pastry to a serving dish. Start by distributing half of the pastry cream over one layer of baked puff pastry.
- Top with another layer of dough, pressing gently to adhere it to the pastry cream below. Spread the remaining pastry cream over the second layer of pastry.
- Top with the third layer of pastry and again press down gently.
- Melt the chocolate in a saucepan over very low heat and transfer it to a pastry bag or decorating tube fitted with a fine round tip. Alternatively, you can use a small plastic bag which has a corner pierced or snipped to make a tiny opening.
- Make the royal icing by beating the egg whites and lemon juice just until foamy. Add most of the confectioners' sugar and mix on low speed until very smooth and glossy.
- Add more confectioners' sugar if necessary to achieve a consistency such that icing drizzled back into the bowl from the beaters will sit briefly on the surface of the icing before sinking back in.
- Immediately pour the royal icing over the top layer of pastry and spread it evenly over the entire surface. Don't worry if some of the icing drips over the edges.
- Next, working quickly before the icing sets, drizzle the chocolate across the icing in evenly-spaced, parallel lines. Again, don't worry if some of the chocolate drips over the edges, and don't worry if your lines look sloppy. The next step will improve their appearance.
- With the tip of a thin, sharp knife, make evenly spaced perpendicular "cuts" through the lines of chocolate, from one side of the pastry to the other. Start by making one cut in one direction, and the next cut in the opposite direction. Continue alternating directions as you work across the surface of the pastry. This creates the classic decorative pattern shown in the photo.
- With a long, sharp knife, cut 1/4 inch off the edges of the pastry all around to make a neat, evenly proportioned rectangle. (Don't discard the scraps -- save them to eat as well!)
- Carefully transfer the trimmed mille-feuille to a serving dish and refrigerate. Allow an hour or two to chill before cutting into individual portions for serving. A long, non-serrated knife will make the cleanest cut through the icing.
