The dough can be made up to 1 week ahead and stored in the refrigerator. You can bake the shell up to 1 day before filling; keep covered at room temperature.
In bowl of an electric mixer fitted with the paddle attachment, cream butter and sugar until light and fluffy, about 2 minutes. Beat in yolks until combined.
In a medium bowl, whisk together flour, cornmeal, and salt; add to yolk mixture, and beat just until a dough forms. Turn out onto plastic wrap; pat into a disk. Wrap in plastic; refrigerate until firm, at least 30 minutes.
Preheat oven to 375 degrees. On a lightly floured work surface, roll out dough to 1/8 inch thick. Fit in a 9-inch tart pan with a removable bottom. Cover with plastic; refrigerate 30 minutes or up to 12 hours.
Place tart pan on a baking sheet. Prick bottom of dough all over with a fork. Line with parchment paper, pressing into edges and up sides. Fill with dried beans, rice, or pie weights. Bake 20 minutes. Remove parchment and weights; continue baking until crust is light golden, about 10 minutes. Transfer to a wire rack to cool at least 15 minutes.