Melt butter in medium metal bowl set over large saucepan of simmering water
Whisk in sugar, lemon juice, lemon peel, and salt; gradually whisk in egg mixture
Whisk until thick and thermometer inserted into curd registers 178-180 degrees; about 8 minutes Transfer to small bowl
Press plastic wrap on top of curd, chill 4 hours (Do Ahead: Can be made 2 days ahead. Keep chilled)
Preheat oven to 400 degrees
Mix pecans, sugar, and butter in medium bowl until moistened
Press pecan mixture onto bottom and up sides of 9 inch diameter glass pie dish (mixture will be crumbly).
Bake until crust is lightly toasted, about 12 minutes (crust will sip down sides of dish as it cooks).
Use back of spoon to press crust back into place
Cool on crust on rack
Freeze crust 30 minutes
Dollop 1 1/2 cups ice cream over crust; spread into even layer
Spread lemon curd over ice cream; freeze until firm, about 2 hours
Dollop 1 1/2 cups softened ice cream over lemon curd, spread into even layer
Cover and freeze until firm, about 2 hours
Using electric mixer, beat egg whites in medium bowl until frothy
Beat in cream of tartar
With mixture running gradually add sugar
Beat until stiff peaks form
Spoon meringue over pie, spreading to seal at edges and swirling decoratively
You can freeze it again at this point if you want or you can cook the meringue and serve
To toast the meringue you can either use a kitchen butane torch, toasting meringue until golden in spots or place pie in a preheated 500 degree oven until meringue is golden in spots, watching to prevent burning, about 5 minutes
Cut pie into wedges, serve immediately
Lemon Curd Ice Cream Pie was originally written by Leigh Anne Wilkes at https://www.yourhomebasedmom.com/marilyns-lemon-curd-and-ice-cream-pie/.