Directions

1. Preheat oven to 375 degrees. In a food processor, combine flour, sugar, salt, and butter; process until large moist crumbs form (dough should hold together when squeezed).
2. Transfer dough to a 9-inch round tart pan with a removable bottom; with floured fingers, press evenly into bottom and up sides. Freeze until firm, about 15 minutes; prick bottom of dough all over with a fork. Bake until golden, 20 to 25 minutes; cool completely.
3. Meanwhile, reserve 1 cup of the prettiest berries for topping. In a medium saucepan, bring 1/4 cup water and 1 1/2 cups berries to a boil over high heat. Reduce heat; simmer, stirring occasionally, until berries begin to break down, 3 to 4 minutes.
4. In a small bowl, mix cornstarch with 2 tablespoons water; stir into berries in pan. Add lemon zest and juice, sugar, and salt. Bring to a boil; reduce heat. Simmer, stirring, just until mixture begins to thicken, 30 to 60 seconds. Remove from heat. Stir in remaining 3 1/2 cups fresh berries. Immediately pour hot berry mixture into cooled tart shell, and smooth with a spatula.
5. Scatter reserved berries on top, pressing down lightly to help them adhere. Refrigerate until cool, about 30 minutes and up to overnight.