Sweet Pastry Crust:  In a separate bowl, sift or whisk together the flour and salt.  Set aside.  Place the butter in your mixer and beat until softened.  Add sugar and beat until light and fluffy. Gradually add the beaten egg, beating just until incorporated.  Don't over mix or the butter will separate and lighten in color.  Add flour mixture all at once and mix just until it forms a ball.  Don't overwork or pastry will be hard when baked.  

Flatten dough into disk, cover with plastic wrap, and refrigerate for about 30 minutes or until firm.

Have ready an 8 - 9 inch (20 - 23 cm) tart pan with removable bottom.  On a lightly floured surface, roll out the pastry into an 11 - 12 inch (28 - 30 cm) circle that is about 1/8 inch (3 mm) thick.  To prevent the pastry from sticking to the counter and to ensure uniform thickness, keep lifting up and turning the pastry a quarter turn as you roll (always roll from the center of the pastry outwards to get uniform thickness). To make sure it is the right size, take your tart pan, flip it over, and place it on the rolled out pastry.  The pastry should be about an inch larger than pan.

When the pastry is rolled to the desired size, lightly roll pastry around your rolling pin, dusting off any excess flour as you roll.  Unroll onto top of tart pan.  Never pull pastry or you will get shrinkage (shrinkage is caused by too much pulling of the pastry when placing it in the pan).  Gently lay in pan and with a small floured piece of pastry, lightly press pastry into bottom and up sides of pan.  Roll your rolling pin over top of pan to get rid of excess pastry.  With a thumb up movement, again press dough into pan.  Roll rolling pin over top again to get rid of any extra pastry.  Prick bottom of dough (this will prevent the dough from puffing up as it bakes).  Cover and refrigerate for about 20 minutes to chill the butter and to rest the gluten in the flour.

Preheat oven to 400 degrees F (205 degrees C) and place rack in center of oven.  Line unbaked pastry shell with parchment paper or aluminum foil.  Fill tart pan with pie weights, rice or beans, making sure the weights are to the top of the pan and evenly distributed over the entire surface.  Bake the crust for 20 to 25 minutes or until the crust is dry and lightly golden brown.  

For Lemon Curd: While the crust is baking make the Lemon Curd.  In a stainless steel bowl placed over a saucepan of simmering water, whisk together the eggs, sugar, and lemon juice until blended.  Cook, whisking constantly (to prevent it from curdling), until the mixture becomes pale in color and quite thick (like a hollandaise sauce or sour cream) (160 degrees F or 71 degrees C on a thermometer).  This will take about 10 minutes.  Remove from heat and immediately pour through a fine strainer to remove any lumps.  Cut the butter into small pieces and whisk into the mixture until the butter has melted.  Add the lemon zest.  Immediately pour the lemon curd into the baked crust and smooth the top.

Reduce the oven temperature to 350 degrees F (177 degrees C).  Bake the tart for about 10 minutes or until the lemon curd is firm but still a little wobbly in the center.  Do not let it brown or burn. 

For Meringue: In a clean bowl of your electric mixer, with the whisk attachment, beat the egg whites until foamy.  Add the cream of tartar and continue beating until soft peaks form.  Gradually add the sugar and continue to whip until stiff peaks form.

Using a spoon, place dollops of the meringue over the entire surface of the hot lemon curd, starting at the outside edge of the tart.  (Make sure the meringue comes right up to the crust and there are no gaps between the crust and the lemon curd.) Then, with the back of your spoon, gently press down on the meringue to get rid of any air pockets and to make sure all the lemon curd is covered with the meringue.  If desired, swirl the meringue making a few decorative peaks.  Return the tart to the oven and bake for about 10 to 15 minutes or until the meringue has nicely browned.

Remove from oven and place on a wire rack to cool, away from any drafts.  When cool, serve or else cover and refrigerate.

Serves 6 - 8

Note:  Leftover pastry can be used to make Sables (French Butter Cookies)

Sources:

Beranbaum, Rose Levy. 'The Pie and Pastry Bible'. Scribner. New York: 1998.

Friberg, Bo. 'The Professional Pastry Chef'. Van Nostrand Reinhold. New York: 1996.

Grigson, Jane. 'Jane Grigson's Fruit Book'. Penguin Books. London: 1982.

Walters, Carole. 'Great Pies and Tarts'. Clarkson/Potter Publishers. New York: 1998.