In a medium bowl, whisk together the flour, almond meal, and salt.
In the bowl of a stand mixer fitted with the paddle attachment, combine the butter and confectioners' sugar and beat on medium until pale, 1 to 2 minutes, using a rubber spatula to scrape down the bottom and sides of the bowl as necessary. Reduce the mixer to low and add the egg, beating until well combined, about 3 minutes, scraping down the bottom and sides of the bowl as necessary. The mixture will still be lumpy, but the butter and egg mixture should look like thick pancake batter.
Add the dry ingredients all at once and continue to beat on low speed until the dough is just combined and clumps around the paddle and sides of the bowl—do NOT mix the dough longer, or the dough will be brittle and hard to roll and I'll cry for you.
Scrape the dough onto a lightly floured counter. Quickly knead it into a rough ball, and flatten to a small disc. Tightly wrap in plastic wrap and refrigerate for at least 1 hour, preferably overnight, before rolling out and shaping to the tart ring. The tart dough will keep in the refrigerator for up to 2 days, and in the freezer for up to 3 months.