Tieton Apricot Tart with Basil Custard

Preheat the oven to 350 degrees F (175 degrees C).

Whisk all-purpose flour, whole wheat flour, almond meal, 1 tablespoon sugar, lemon zest, and salt together in a large bowl; cut in butter with a pastry blender until mixture forms pea-sized crumbs. Stir in buttermilk until dough comes together.

Press dough into the bottom and ½ inch up sides of a 16x12-inch baking pan or baking sheet.

Bake in the preheated oven until lightly browned, about 20 minutes. Cool completely on a wire rack, about 1 hour.

Meanwhile, whisk egg yolks, ⅔ cup sugar, and cornstarch together in a heavy-bottomed saucepan; whisk in milk. Add basil; cook over medium heat, whisking constantly, until mixture begins to steam, about 8 minutes. Reduce heat to low and discard basil. Whisk vigorously until custard thickens, about 1 minute.

Set a mesh strainer over a large bowl. Pour custard through strainer; press it through using a rubber spatula. Whisk vanilla extract into custard. Press a piece of plastic wrap directly onto custard surface. Refrigerate until cold, about 3 hours.

Pour custard into crust; spread to edges with a rubber spatula. Arrange apricot slices on top.

Place apricot jam in a small microwave-safe bowl; microwave on high until melted, about 1 minute. Brush jam over apricot slices.