Boil gooseberry with sugar, until sugar melted. Mash gooseberries a little if you like, while boiling.
Mix cornstarch in water, then pour mixture into the pot. Stir. It will thickened. Take off from heat, cool to room temperature.
Beat cream cheese with icing sugar, then beat in cooled gooseberry, until creamy.
Open puff pastry and lay on clean flat surface, slice into squares. On each side (watch the vlog), make slices but not cutting through.
Preheat oven to 400 F
Brush sides of puff pastry with beaten yolk, and spoon gooseberries cream to center. Bake for 20-25 mins