Preheat oven to 400°F.
Thaw 1 sheet of frozen puff pastry dough. Cut into 6 rectangles, approximately 4 ¼-by-3 inches each.
Place the rectangles on a parchment lined baking sheet. Score each pastry with a sharp knife, about ½-inch from the outer edge, all the way around making a rectangle inside the rectangle. Do not cut all the way through. Pierce the center of each pastry with a fork. Whisk together the egg and milk. Brush the edges of each pastry shell with the egg wash.
Bake the pastry shells for 15-20 minutes or until they puff up and are golden brown. Remove to a rack to cool completely. If needed, cut around the inner rectangle with a small paring knife and press the center down lightly to create an indentation. Once cooled, store lightly covered at room temperature until ready to assemble.
In a small bowl combine the blueberries and honey. Set aside or refrigerate until ready to serve.
In a small bowl combine the mascarpone cheese and powdered sugar. Beat with an electric mixer until smooth. Turn the mixer on low and slowly add the whipping cream until it's incorporated and starting to thicken. Increase the speed to medium, then high and beat until medium soft peaks form. It won't take long. Gently fold in the lemon curd with a spatula until blended. If making ahead, cover and refrigerate until ready to assemble.
To serve, divide the lemon cream mixture on top of the pastry shells. Top each with the blueberry mixture and toasted sliced almonds. Dust with powdered sugar and serve immediately.