Make pastry by pulsing flour, slat, shortening and butter in food processor until course lumps. Slowly add water with quick pulses between additions until just holding together. Press into a disk and wrap tightly in plastic wrap. Refrigerate at least 30 minutes to chill.
Divide dough in half. Return half to the refrigerator, wrapped in plastic. On a well floured surface roll first half of dough into a circle about 2 inches larger than the pie plate outer edge. Turn and flip dough as needed while rolling to prevent sticking.
Using a rolling pin, gently roll pastry over top and unroll over pie plate. Adjust as necessary to fit evenly in pie plate. Do not trim edges yet. Refrigerate while preparing filling.
Preheat oven to 400 degrees and ensure rack is in lower setting.
To prepare filling, beat eggs very well until they are very frothy, expanding and light yellow. Add all other ingredients and pour into pie shell.
Roll out second half of dough into a rectangular shape using same turning and flipping method as for bottom shell. Using a sharp knife or pizza cutter, slice into even strips approximately half inch wide. Brush water on outer edge of bottom crust. Arrange half of the strips over top of pie, using longest strips across the widest part of the pie.
Create lattice top by folding back alternate strips in each row and placing strips across diagonally. Fold strips back in place, fold back alternate strips and lay second row of strips, repeating until entire pie top is covered evenly in lattice pattern as shown above in photos.
Press edges of pie crust to seal pastry in place. Trim excess from edges and crimp to seal and finish edge.
Bake on lower rack of preheated oven for 10 minutes. Reduce heat to 350 and bake for 35-38 minutes until top is browning and filling is bubbling.