Twelve to 24 hours before you want to bake the pie:
Slice the lemons as thin as possible. Put them in a bowl with the 2 cups of sugar. Stir to coat and let them sit.
When you're ready to make the pie:
Preheat the oven to 450. Add the beaten eggs to the lemon mixture, and the salt, if you're using it. Mix well.
Roll out your first disk of pie dough for the bottom crust. Line a 9-inch pie pan with it. Pour in the lemon filling.
Roll out your second disk of pie dough for the top crust. Cut vents in the top crust. (Kate and some other pie bakers cut vents later in the process, but for me, it works best at this stage of the game.) Cover the top of the pie with the vented crust. Finish edges and crimp.
Chill the pie for a good half-hour. Remove from fridge. Brush with egg white; sprinkle with sugar.
Bake at 450 for 15 minutes. Reduce heat to 375 and bake for about 25 minutes, checking the pie at the 20-minute mark.