Tarte Au Citron

Roll out half the dough 1/8-inch thick on a floured surface. Press it
firmly into an 8-inch tart pan with a removable fluted rim. Trim off
excess dough, leaving a 1/2-inch overhang. Fold the overhang back
inside the rim, pressing it to the side of the shell, and push the
dough up 1/4-inch above the edge of the pan. Crimp the edge
decoratively with a fork. Roll out remaining dough and make up
another tart shell in the same manner.

Chill the shells for 60 minutes. Line the shells with foil, fill the
foil with rice and bake in the lower third of a preheated 400f oven
for 8 minutes. Remove the rice and foil, and bake for 8-10 minutes
more or until they are pale golden. Remove shells from the pans,
transfer them to a rack and let them cool.

In a bowl with an electric mixer, beat the egg yolks with 1/2 cup
sugar until the mixture is thick and pale and forms a ribbon. Beat
in the zest and lemon juice. Transfer the mixture to a heavy
saucepan. Cook it, stirring constantly with a wooden spoon, over
mod-low heat, until it registers 140f on a candy thermometer.
Continue to cook at a stable 140f for 3 minutes longer. Do not let
it boil. Transfer the mixture to a bowl, and let it cool, covered
with a buttered round of wax paper, until it is luke-warm.

In a bowl, beat the egg whites with a pinch of salt until they hold
soft peaks. Add the remaining 1/4 cup sugar, one Tbsp at a time, and
beat the meringue until it just hold stiff peaks. Stir a quarter of
the meringue into the lemon mixture and fold in the remaining
meringue gently but thoroughly.

Transfer the tart shells to a baking sheet and fill with the lemon
mixture, mounding it slightly. Bake the tarts in the middle of a
preheated 400f oven for 12-15 minutes, or until the tops are golden
and puffed. Transfer the tarts to a rack and let them cool.