How to Make It
Prepare the crust: Whisk together 75 ounces flour, white sesame seeds, 1/2 teaspoon salt, and baking powder in a large bowl. Add shortening and 1 tablespoon butter to flour mixture; combine, using your fingers, until shortening and butter are well distributed and small clumps begin to form. Stir in vodka. Add up to 3 tablespoons ice-cold water, 1 tablespoon at a time, stirring just until dough begins to come together. Turn dough out on a lightly floured surface; gently knead 1 to 2 times. Shape into a ball; flatten into a disk, and wrap tightly in plastic wrap. Chill for 20 minutes.
Unwrap dough, and transfer to work surface. Roll to a 10- to 11-inch circle; fit into a 9-inch glass pie plate. Fold edges under, and crimp. Freeze for 40 minutes (or up to 2 months).
Preheat oven to 350°F.
Prepare the filling: Melt 3 tablespoons butter in a small skillet over medium. Cook, stirring often, until butter begins to brown, about 5 minutes. Cool completely, about 10 minutes. Combine sugar and zest in a large bowl; rub zest into sugar using your fingers to release oils. (Sugar will feel slightly moistened, and zest will release a lemony scent.) Whisk together milk, eggs, and yolks in a medium bowl; stir milk mixture into sugar mixture. Stir in cornmeal, 2 tablespoons flour, and 3/4 teaspoon salt until well combined. Stir in tahini, browned and cooled butter, vinegar, and vanilla; whisk until smooth. Remove crust from freezer. Pour sugar mixture into crust.
Bake on center rack at 350°F for 35 minutes. Remove from oven; top with black sesame seeds. Return to oven; bake until set around edges, 7 to 8 more minutes. (Center will still be slightly wiggly.) Cool 45 minutes to 1 hour; serve chilled or at room temperature.
Note: We recommend seeking out Earth Balance shortening because, unlike most other shortenings, it contains no trans fats.