Preheat the oven to 400°F (200°C).
Roll out the puff pastry on a lightly floured surface.
Cut the pastry into 4 squares, approximately 4x4 inches each.
In a mixing bowl, combine cream cheese, powdered sugar, vanilla extract, and lemon juice.
Fold in the chopped strawberries gently until combined.
Spoon the filling onto the center of each pastry square.
Fold the corners of the pastry over the filling to form triangles, then press and crimp the edges to seal.
Brush the tops of the turnovers with the beaten egg for a golden finish.
Place the turnovers on a lined baking sheet and bake for 20-25 minutes.