1
: Beat egg yolks; whisk in lemon rind, sweetened condensed milk and lemon juice. Pour into prepared crust.
2
: Bake in preheated 325°F (160°C) oven for 25 minutes. Remove from oven. Increase oven temperature to 350°F (180°C).
3
: Beat egg whites with cream of tartar until foamy; gradually add sugar beating until stiff peaks form but not dry. Spread meringue on top of hot pie, sealing carefully to edge of crust.
4
: Return to oven and bake for 10 minutes or until meringue is golden brown. Cool. Chill before serving, if desired.