📋 Instructions

1. 1Make the crust dough — Pulse the flour, powdered sugar, and salt in a food processor, then add the cold butter and pulse until it looks like coarse sand. Add the egg yolk and pulse just until the dough clumps together; overworking it makes the crust tough.
2. 2Chill the shell — Press the dough evenly into a 9-inch tart pan, prick the base with a fork, and freeze it for 20 minutes. This firm set stops the sides from sliding down during baking.
3. 3Blind-bake at 350F (175C) — Line the shell with parchment and fill it with pie weights, then bake at 350F (175C) for 20 minutes. Remove the weights and parchment and bake 8 to 10 minutes more, until the crust is golden brown and smells like toasted shortbread.
4. 4Whisk the lemon filling — Whisk the eggs, yolks, sugar, lemon juice, and zest in a saucepan until smooth. Cook over low heat, stirring constantly with a whisk, for 6 to 8 minutes, until the mixture coats the back of a spoon and the first lazy bubble breaks the surface.
5. 5Finish the curd — Pull the pan off the heat and whisk in the butter one tablespoon at a time until glossy, then strain through a fine sieve. Pour the warm curd into the baked shell and smooth the top with an offset spatula.
6. 6Bake at 325F (165C) — Bake the filled tart at 325F (165C) for 10 to 12 minutes, until the edges are set and the center still jiggles gently when you nudge the pan. It will look slightly underdone, and that is exactly right.
7. 7Cool and chill — Let the tart cool completely on a rack, about 1 hour, then refrigerate for at least 2 hours. Chilling sets the curd so your slices come out clean instead of weeping.
8. 8Top with blueberries — Arrange the blueberries in a loose spiral over the chilled surface, dust lightly with powdered sugar, and serve on a white plate. Listen for the soft pop of a berry as the first fork goes in.