Combine flour, nut meal and salt in a large bowl. With a pastry blender or two knives, cut in shortening and butter until the mixture resembles coarse crumbs. Using a fork, mix in just enough water to form a cohesive mass. (This can also be done in a food processor.)
Using your hands, shape the dough into a ball, then flatten slightly into a disk. Wrap in plastic wrap and refrigerate until dough is chilled enough to roll (at least 30 minutes).
Flour a work surface. Divide dough into two parts, one slightly larger than the other. Roll the larger piece to a 1/8” thickness, sprinkling it lightly with flour as needed so it doesn’t stick. Carefully fold in half and transfer to a 9” pie or tart pan. Ease into bottom and up sides of pan. Trim away excess dough, leaving about a 1” overhang.
Fill pie. Roll out smaller piece of dough and drape over filling. Trim edges and pinch to seal. Make several slits in top crust so steam can escape. Bake as directed in your pie-filling recipe.