The recipe for this scrumptious tart came from the Cullen Winery in Margaret River, Australia. They used mulberries but if those are hard to find, blackberries, raspberries, or a combination of the two will work equally well.
FOR THE PASTRY:
2 cups flour
2 tbsp. sugar
1⁄4 tsp. salt
12 tbsp. chilled butter, cut into small pieces
4 tbsp. chilled vegetable shortening
1 egg, lightly beaten
FOR THE FILLING:
1 1⁄4 cups superfine sugar
2 1⁄2 cups mulberries, blackberries, or raspberries
6 tbsp. heavy cream
1. For the pastry: Sift together flour, sugar, and salt into a large mixing bowl. Use a pastry cutter or two knives to work butter and vegetable shortening into flour until it resembles coarse meal. Sprinkle in up to 8 tbsp. ice water, stirring dough with a fork until it begins to hold together. Press dough into a rough ball, transfer to a lightly floured surface, then flatten slightly with your hand to make a round. Wrap dough in plastic wrap, and refrigerate for 2 hours.
2. Preheat oven to 400°. Roll dough out on a lightly floured surface into a 14" round, fit into a 12" fluted false-bottom tart pan, and run rolling pin over rim to remove overhanging dough. Prick bottom with a fork. Line dough with parchment, add pie weights or dried beans, and bake until crust is set and edge begins to color, about 25 minutes. Reduce oven temperature to 350°, remove parchment and weights, brush bottom and sides with egg, and continue baking until crust is golden, 15–20 minutes longer.
3. For the filling: Whisk together eggs and sugar in a medium mixing bowl until pale yellow. Purée 1 1/2 cups of the berries in a blender, and stir into egg mixture. Remove the zest from half the lemon, then squeeze juice from lemon and add both to egg mixture. Add cream; mix well. Arrange remaining 1 cup berries evenly on crust, pour in filling, and bake until filling is set, about 40 minutes. Set aside to cool before serving.