As with traditional icebox desserts, this tangy pie should be served cold. It's delicious by itself, or you can spoon a dollop of whipped cream onto each wedge.
Preheat oven to 350 degrees, with rack on lowest level. Spread pecans on a rimmed baking sheet, and toast in the oven until golden, tossing occasionally, about 10 minutes. Let cool.
In a food processor, finely grind graham crackers, sugar, and pecans. Add the butter, and process until completely combined.
Press mixture into bottom and up sides of a 9-inch pie pan. Bake until crust is lightly browned, about 8 minutes. Let cool on a wire rack.
In a large bowl, beat the egg yolks with the condensed milk. Stir in the lemon juice. Spoon filling into cooled pie crust. Bake until filling is set and crust is golden brown around the edges, about 15 minutes. Let cool slightly, then refrigerate until well chilled, at least 1 hour.
Cookie crusts don't require rolling or trimming. The mixture might seem loose, but it will come together when pressed into the pan and baked.