Combine the flour and sugar in a large mixing bowl. Add the cold, cubed butter and use a pastry cutter or fingertips to work it into the flour until the mixture resembles coarse crumbs with some pea-sized chunks. This creates the flaky crust base.
1 cup all-purpose flour, 1/4 cup granulated sugar, 1/2 cup unsalted butter
Add the egg yolk to the flour mixture and gently knead until the dough comes together. Press the dough into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes to firm up.
1 large egg yolk
Preheat the oven to 375°F (190°C). Roll out the chilled dough on a lightly floured surface into an even circle about 1/8 inch thick. Transfer the dough to the tart pan and press into the edges, trimming excess dough.
1 cup all-purpose flour
Line the crust with parchment paper and fill with pie weights or dried beans. Bake in the preheated oven until golden around the edges, about 15 minutes. Remove the weights and parchment, and bake for an additional 5 minutes until fully cooked. Allow to cool slightly.
In a bowl, gently toss the mixed berries with honey and lemon juice until well coated. Spread the berry mixture evenly over the cooled crust.
2 cups mixed berries, 1/4 cup honey, 1 tablespoon lemon juice
Optional: arrange some whole berries on top for presentation. Chill the tart in the refrigerator for at least 30 minutes before serving to allow the flavors to meld.
