Step 1

The day before, make the lavender sugar. (see notes)

Step 2

Set your puff pastry out 20 to 25 minutes before unfolding and rolling out on a lightly floured surface to a 12x12 square. Then cut into 4 squares.

Step 3

Brush a little of the beaten egg on the outer edge of each square and fold to create a edge or crust. Use a fork to dock the center of the dough.

Step 4

Place the four squares onto a parchment lined, rimmed metal baking sheet and freeze fro 25 minutes.

Step 5

Meanwhile, preheat your oven to 425°.

Step 6

In a medium bowl, combine the blueberries, sugar, lemon, salt and cornstarch, tossing to combine.

Step 7

Once the pastry is frozen, divide the blueberry mixture among each one and dot with a piece of butter.

Step 8

Bake on the middle rack of your preheated oven for 18 to 20 minutes or until the pastry is golden and flakey, and the blueberries have burst.