Grease (or use cooking spray) a 9” glass pie plate.
In large bowl, beat 4 egg whites with cream of tartar until stiff, but not dry. Add sugar slowly until stiff and glossy.
Spread meringue in pie plate, making a “well” in the center for the filling.
Bake at 300 degrees for 1 hour. Turn off the heat and leave crust in oven for at least one hour or, preferably, overnight.
In small, heavy saucepan, whisk together egg yolks, lemon juice, and sugar. Heat over medium-low heat until mixture thickens and starts to bubble. Remove from heat and transfer to a large bowl. Cover with plastic wrap and allow to cool to room temperature.