My mother used to make lemon merigue pies all the time - it was one of the best desserts she made. Usually she would make two at a time. My mother used the My-T-Fine brand lemon pudding mix for her filling. If you grew up on the East Coast you probably remember this brand. It is very difficult to find anymore but Amazon's grocery division is a great source.
The recipe below is one that has been adapted from Saveur magazine and relies upon a lemon curd that is very easy to make and packs a powerful tart punch!
8 tbsp (1 stick) butter
1/2 cup plus 1 tbsp fresh lemon juice
1 1/2 cup sugar
5 eggs, separated
1 tbsp plus 2 tsp cornstarch
Baked pie crust
1. Preheat oven to 400 degrees. Prepare pie crust and place in 9” pan. Place pie weights or dried beans on aluminum foil and place in center of pan. Bake for 12 minutes. Remove from oven, remove foil and weights, prick bottom with a fork and bake another 10 minutes until brown.
2. Filling: in a small pot combine butter, lemon juice and ¾ cup sugar and heat over medium heat until bubbles form around the edges. Meanwhile whisk 1 egg white and 5 egg yolks and ½ cup sugar in large bowl until thick and pale then whisk in cornstarch.
3. Drizzle hot lemon mixture into egg mixture while whisking constantly. Cook mixture over medium heat, stirring constantly, until it is as thick as pudding, about 10 minutes.
4. Place filling in a bowl, cover with plastic wrap and chill in the refrigerator. Place into cooled pie crust and smooth to cover the bottom. Refrigerate for 2 hours.
5. Meringue: beat 5 egg whites until soft peaks form then add ¼ cup sugar and beat until still peaks forms. Cover filling and edges of crust with meringue. Bake for 2 minutes in a 475 degree oven until brown areas appear on the meringue. Refrigerate until ready to serve.