In a mixing bowl, whisk together the egg yolk and heavy cream until combined. In a food processor, pulse the all-purpose flour, confectioners’ sugar, and kosher salt until mixed. Add the chilled unsalted butter, processing until the mixture resembles coarse crumbs. Gradually blend in the egg mixture until a dough forms. Chill the dough in the refrigerator for 1 hour.

Preheat your oven to 350°F (175°C) and prepare a 9-inch tart pan. Roll out the chilled dough on a floured surface, then carefully fit it into the tart pan, trimming any excess dough. Refrigerate the crust for 15 minutes to firm it up. Once chilled, bake for 20-25 minutes, or until the crust is golden brown. Allow it to cool completely on a wire rack.

While the tart crust cools, prepare the lemon curd. In a saucepan over medium heat, whisk together the lemon juice, lemon zest, eggs, and honey. Cook the mixture, stirring constantly, until it thickens and coats the back of a spoon, about 5 minutes. Remove from heat and stir in the cold unsalted butter until melted. Strain the curd through a fine-mesh sieve into the cooled tart crust.

Once the lemon curd is poured into the tart crust, carefully place the tart back in the oven. Bake for an additional 10-12 minutes, or until the lemon filling is set but slightly jiggly in the center. Remove the tart from the oven and let it cool at room temperature for about 30 minutes.

While the tart cools, make the blueberry layer. In a blender, puree the blueberries until smooth, then strain the mixture through a fine-mesh sieve to remove any seeds. In a saucepan, combine the strained blueberry puree, honey, and cornstarch. Simmer over medium heat for about 4 minutes, stirring constantly, until the mixture thickens.

Once the blueberry mixture has thickened, carefully pour it over the cooled lemon curd layer in the tart crust. Smooth the top gently with a spatula, ensuring even coverage. Refrigerate the assembled Blueberry Lemon Curd Tart for at least 2 hours, allowing the layers to set properly.

Once fully chilled, slice the tart and serve with a dollop of whipped cream or a scoop of lemon sorbet for an added treat.