Directions

1. Make the crust: in the bowl of a mixer, cream together butter and sugar. Add egg yolk and the milk, and beat to combine. In a medium bowl, combine the flour with salt. Slowly add the flour to the butter mixture, stirring until completely blended. Gather dough into two balls. Freeze one for future use, chill the other for at least 1 hour.

2. Heavily butter a 10-inch tart pan with a removable bottom. Press the dough into the pan and trim the edges. Prick the bottom with a fork, and place the shell in the freezer for 30 minutes.

3. While shell is in freezer, prepare lemon curd. Grate zest of lemons. Squeeze lemons to extract 1 cup of juice. In a medium nonreactive saucepan, combine juice and zest. Add remaining sugar, butter and salt. Place over medium heat, stirring once or twice, until sugar is dissolved and the butter is melted.

4. In bowl of a mixer, combine eggs and egg yolks until blended. Slowly add hot lemon mixture to eggs until blended. Return mixture to saucepan, and place over low heat. Whisk constantly until mixture thickens to a pudding-like consistency; do not allow it to boil. Remove from heat, and continue to stir to stop the cooking. Strain lemon curd into a bowl. Adjust sugar to taste; the curd should be tart, but may need additional sugar if the lemons were unripe. Cover with plastic wrap, pressing it right against the surface of the curd. Allow to cool.

5. Heat oven to 375 degrees. Remove tart shell from freezer, and bake until lightly golden, 20 to 25 minutes. Remove from heat and allow to cool slightly. Spoon lemon curd into tart shell, and smooth the top. Bake until filling has puffed around the edges, about 30 minutes. Cover edges with foil, if necessary, to prevent over-browning. Cool to room temperature before serving.