Follow these simple steps to create your Blueberry Cheesecake Fillo Galette:

1. Preheat the Oven: Set your oven to 375°F (190°C) and line a baking sheet with parchment paper.
2. Prepare the Fillo Dough: Lay one sheet of fillo dough on the prepared baking sheet. Brush lightly with melted butter and top with another sheet. Repeat this process until you have layered four sheets of fillo.
3. Make Cheesecake Filling: In a medium bowl, combine the softened cream cheese, Greek yogurt, granulated sugar, vanilla extract, and salt. Whisk until smooth.
4. Add Egg: Mix in the egg until fully incorporated.
5. Prepare Blueberries: In a separate bowl, toss the blueberries with cornstarch and lemon juice. This helps to thicken the filling and enhances the flavor.
6. Spread Filling: Pour the cheesecake filling onto the center of the fillo dough, spreading it out evenly while leaving a margin around the edges.
7. Add Blueberries: Layer the blueberry mixture on top of the cheesecake filling, ensuring even distribution.
8. Fold the Edges: Gently fold the edges of the fillo dough over the filling, creating a rustic border.
9. Brush with Butter: Brush the exposed edges with the remaining melted butter to enhance browning.
10. Bake: Place the galette in the preheated oven and bake for 25-30 minutes, or until the fillo is golden brown and crispy.
11. Cool: Remove from the oven and allow it to cool for about 15-20 minutes before slicing.
12. Dust with Sugar: If desired, dust with powdered sugar just before serving for an elegant touch.

These straightforward instructions will guide you in preparing an exquisite Blueberry Cheesecake Fillo Galette that is both visually appealing and delicious.