In a large mixing bowl, place the flour, butter and water.

Mix with hands until everything is combined and the dough becomes one solid mass.

Turn the dough onto a well-floured board and form into a disk.

Wrap the disk with plastic and refrigerate for at least 30 minutes.

Preheat oven to 400 F.

Roll out almond paste to about an 8-inch circle. Set aside.

Remove dough from refrigerator.

Cut a piece of parchment the size of a baking sheet.

Sprinkle with flour and roll dough on the parchment to form a 12-inch circle.

Leaving about 1 1/2-inches around the perimeter of the dough, set the almond paste in the center.

Next, pile the blueberries in the center of the (rolled out) almond paste.

Gently fold the border up and around the almond paste, pleating as you go.

Brush egg wash around the edges and sprinkle with sugar and sliced almonds.

Bake for 40 minutes until the crust is golden and berries are soft.

Allow to cool.

Serve at room temperature.