Sweet apple and berry sandwich: the recipe for a dessert that everyone will like

Roll out the puff pastry and cut strips on one side.
Cook the berries in a saucepan with the sugar and cornstarch.
Fill the puff pastry with the berry mixture and the diced apple.
Roll up and use the previously cut strips to decorate.
Brush with beaten egg and sprinkle with sugar.
Bake in a preheated oven at 200° for 20-30 minutes.