1. To make the crust: In a food processor, pulse the flour, salt, and sugar to mix. Add the butter and pulse until the mixture resembles coarse meal with pea-sized pieces. Sprinkle the ice water on top and pulse until large clumps form. Press the dough into a disk, wrap tightly in plastic wrap, and refrigerate until firm, about 1 hour. 2. On a lightly floured work surface, roll the dough into a 12-inch round. Fit into a 9-inch pie dish. Tuck in the overhang and decoratively crimp the edges. Freeze while heating the oven. 3. Preheat the oven to 350°F. Prick the bottom of the dough all over with a fork. Line with parchment paper and fill with pie weights or dried beans. Bake until the is golden and dry, about 20 minutes. Remove the parchment and pie weights. Return the crust to the oven and continue baking until golden brown, about 5 minutes. Let cool slightly on a wire rack. 4. Meanwhile, make the filling: In a large bowl, whisk the eggs and sugar. Continue whisking while adding the butter, then the bourbon. Stir in the flour until well combined. Stir in the walnuts and chocolate chips. Pour into the warm pie shell. 5. Bake until the filling is set and the top golden, about 30 minutes. Cool in the pan on a wire rack. Serve warm or room temperature.