Chocolate Pudding without butterscotch vegetables

For pastry dough: 1 1/4 cups all-purpose flour 3/4 stick cold unsalted butter, cut into 1/2-inch cubes 2 tablespoons cold vegetable shortening 1/4 teaspoon[...]

1/2 cup sugar 2 tablespoons cornstarch 4 ounces fine-quality bittersweet chocolate (not unsweetened) 1 1/3 cups whole milk 1 large egg yolk 1 tablespoon[...]