1 cup sugar
3 TBSP cornstarch
1 cup milk
1/4 cup lemon juice
3 egg yolks, slightly beaten
1/3 cup butter
1 TBSP grated lemon peel
1 cup sour cream
Combine sugar and cornstarch in a saucepan. Stir in milk, lemon juice and egg yolks. Cook over medium hear, stirring constantly, until thick. This will take about 10 minutes, but it will feel longer!
Remove from heat. Stir in butter until melted. Add lemon peel. Cool. Fold in sour cream. Spoon into graham cracker crust. Refrigerate.
Whenever I make this pie, I also make a batch of macaroons with the 3 egg whites. How's that for efficient?

Enjoy!