This from-scratch lattice-top peach slab pie recipe feeds a crowd.
Combine flour, salt, and sugar in the bowl of your food processor. Chop cold butter, and add to flour mixture by pulsing several times. Drizzle in ice water, pulsing food processor just until dough holds together. (If you are new to pie dough, add a little extra water to help dough hold together; just add plenty of flour while rolling dough out.)
Turn dough out onto a lightly floured surface and gather into a ball. Divide in 2, flatten into discs, and wrap each tightly with plastic wrap.
Chill both discs 30 minutes, but preferably longer, in the refrigerator. Meanwhile prepare the filling.
Grease a half-size rimmed baking sheet (12 x 17 x 1 inches) and set aside. Clear some space in your freezer to chill bottom crust.
On a parchment-lined, lightly floured large working space roll out dough for the bottom crust. Your rectangle should be about 15 x 20-inches. Working quickly, fold dough into quarters, and unfold in greased cookie sheet. Trim all but 1-inch of crust from the edges. Place in freezer while you prepare top crust.
Roll out top crust. With a sharp knife, cut into 1-inch strips.
Remove bottom crust from freezer, spoon filling into cold shell, and then work quickly to weave your lattice over the top. (For a step-by-step guide on lattice weaving, click here.) Crimp up edges. Brush egg white on top and sprinkle with sugar.
Bake 45 - 55 minutes, or until filling is bubbling and crust is a light golden hue. Cool several hours before serving.