1 box frozen puff pastry, defrosted in fridge
1 16-oz bag frozen mixed berries
juice of 1 lemon
1/2 cup sugar + more for sprinkling
2 T cornstarch + 2 T cold water
1 egg + 1 T warm water
Whisk together the cold water and cornstarch in a small bowl until all the cornstarch is dissolved. Set aside.
Combine the berries, lemon juice and sugar in a saucepan and heat over medium high on the stove. Once the berries have burst and the mixture has started to simmer, slowly drizzle in the cornstarch/water and stir constantly while bringing up to a boil. Boil until thick, about 4-5 minutes. Remove from heat and let cool while you prepare the pastry.
Preheat oven to 375.
with one piece of puff pastry at a time, roll out to smooth edges and
then slice into six equal sized squares. Place squares on a lined baking
Place 1-2 tbsp berry mixture onto half of the pastry. Carefully fold over pastry and pinch all edges together well. Make three small slits into the top of each.
Whisk together the egg and water well then brush on each pie. Sprinkle a teaspoon of sugar over each.
Bake for 30 minute until golden brown.