01 - In a mixing bowl, blend flour, powdered sugar, and salt. Incorporate the cold butter using fingertips or a pastry cutter until the mixture forms fine crumbs.
02 - Add egg yolk and 1 tablespoon cold water. Gently mix until the dough holds together, adding more water if necessary.
03 - Shape dough into a disk, cover with plastic wrap, and refrigerate for at least 20 minutes.
04 - Preheat oven to 350°F. Roll out chilled dough on a lightly floured surface to 1/8 inch thickness. Cut circles approximately 3 inches in diameter and press into tartlet pans. Trim edges and prick bottoms with a fork.
05 - Line shells with parchment paper and fill with baking weights or dried beans. Bake for 12 minutes, remove weights and parchment, then bake 8 minutes more until golden. Cool completely.
06 - In a heatproof bowl, combine eggs, sugar, lemon juice, and zest. Place over simmering water and whisk continuously until thickened, about 8 to 10 minutes.
07 - Remove from heat and whisk in cubed butter until smooth. Allow to cool for 10 minutes.
08 - Spoon or pipe lemon curd into cooled shells evenly.
09 - Refrigerate tartlets for a minimum of 30 minutes before serving. Garnish as desired with fresh berries, powdered sugar, or lemon slices.