Combine Dry Ingredients: In a large bowl, whisk together the all-purpose flour, powdered sugar, and salt.

Cut in the Butter: Add the cold, cubed butter to the flour mixture. Using a pastry blender or your fingertips, cut the butter into the flour until the mixture resembles coarse breadcrumbs.

Form the Dough: In a small bowl, lightly whisk the egg yolk with one tablespoon of ice water. Drizzle this over the flour mixture and gently toss with a fork until the dough starts to come together.

Chill the Dough: Form the dough into a flat disc, wrap it tightly in plastic wrap, and refrigerate for at least 30 minutes.

Press Into Pan: Unwrap the chilled dough and press it evenly into the bottom and up the sides of a 9-inch tart pan with a removable bottom.

Blind Bake the Crust: Freeze the crust for 15 minutes. Preheat oven to 375°F (190°C). Line the tart shell with parchment paper and fill with pie weights. Bake for 15 minutes. Remove parchment and weights, then bake for another 5-7 minutes until pale golden brown. Let it cool completely.

Whisk Eggs and Sugar: In a medium bowl, vigorously whisk the granulated sugar and eggs together until the mixture is pale and slightly thickened, about 2 minutes.

Add Lemon: Whisk in the fresh lemon juice and lemon zest until well combined.

Incorporate Butter: Slowly drizzle in the melted butter while continuing to whisk until the mixture is smooth and emulsified.

Strain the Mixture: For an extra-silky texture, pour the filling through a fine-mesh sieve into another bowl.

Prepare for Baking: Reduce the oven temperature to 325°F (160°C). Place your cooled, pre-baked tart crust on a baking sheet.

Add Blueberries: Arrange the fresh blueberries in a single layer across the bottom of the crust.

Pour the Filling: Carefully pour the lemon filling over the blueberries.

Bake to Perfection: Bake for 30-35 minutes, or until the center of the filling is just set. It should have a slight wobble when you gently shake the pan.

Cool Completely: Let the tart cool completely on a wire rack for at least 1 hour. Then, transfer to the refrigerator to chill for at least 4 hours before serving.