Smoked Sturgeon Napoleon with Caviar Cream and a Lemon Gastrique
For the Lemon Gastrique: Combine champagne vinegar, lemon zest, and sugar in a medium non-reactive saucepan and bring to a boil. Continue to cook until sugar has melted and liquid has reduced to nappe consistency and coats the back of a spoon, about 4 to 5 minutes. Remove to a non-reactive bowl and set aside to cool to room temperature before drizzling over Smoked Sturgeon Napoleons with Caviar Cream. Can be made well in advance and refrigerated until ready to use, but should be returned to room temperature before serving.
Preheat oven to 400 degrees F.
On a lightly floured work surface, roll out puff pastry to a thickness of 1/8 inch. Using cookie cutter or a very sharp knife, cut pastry into 12 (3-inch) portions of the desired shape. Place pastry pieces on top of a sheet pan covered with parchment paper, cover pastry with another sheet of parchment paper and top with another sheet pan of the same size. Bake in a preheated oven until crispy and golden brown, about 10 minutes. Remove pastry from oven and transfer to a cooling rack. Set aside until ready to assemble napoleons.
On 4 appetizer plates, arrange 1 piece of baked puff pastry on top of a 1/2 teaspoon of the caviar cream (this will anchor the Napoleon). Divide smoked sturgeon into 8 portions. Top each piece of puff pastry with 2 tablespoons of caviar cream and 1 of the portions of smoked sturgeon. Top with another piece of puff pastry and repeat layering process, ending with a piece of puff pastry. Drizzle each napoleon with lemon gastrique and serve immediately, garnished with chopped chives and any extra caviar cream.