For tart shell:
- 1 1/4 cups all-purpose flour
- 3 tablespoons granulated sugar
- Rounded 1/4 teaspoon salt
- 7 tablespoons unsalted butter, cut into 1/2-inch pieces
- 1 large egg yolk
- 1/2 teaspoon pure vanilla extract
- 1/2 teaspoon fresh lemon juice
- 3 tablespoons cold water
- 1 1/2 pounds strawberries (about 1 1/2 quarts), trimmed and halved lengthwise
- 1/3 cup granulated sugar
- 3/4 cup ruby Port
- 1 pound mascarpone (about 2 cups)
- 1/4 cup confectioners sugar
- 1 teaspoon fresh lemon juice
- 1/2 teaspoon grated lemon zest
- 3/4 teaspoon pure vanilla extract
- Make tart shell:
Blend together flour, sugar, salt, and butter in a bowl with your fingertips or a pastry blender (or pulse in a food processor) just until mixture resembles coarse meal with some roughly pea-size butter lumps. Beat together yolk, vanilla, lemon juice, and water with a fork, then drizzle over flour mixture and stir with fork (or pulse) until mixture comes together.
Gently knead with floured hands on a lightly floured surface until a dough forms, then gently knead 4 or 5 times. Press into a 5-inch disk. Place in center of tart pan and cover with plastic wrap. Using your fingers and bottom of a flat-bottomed measuring cup, spread and push dough to evenly cover bottom and side of pan. Prick bottom of tart shell all over with a fork and freeze until firm, about 10 minutes.
Preheat oven to 375°F with rack in middle.
Line tart shell with foil and fill with pie weights. Bake until side is set and edge is pale golden, about 20 minutes. Carefully remove foil and weights and continue to bake until shell is deep golden all over, about 20 minutes more. Cool in pan, about 45 minutes.
- Make filling while tart shell cools:
Stir together strawberries and granulated sugar in a bowl and let stand, stirring occasionally, 30 minutes. Strain in a sieve set over a small saucepan, reserving berries. Add Port to liquid in saucepan and boil until reduced to about 1/4 cup, 10 to 15 minutes. Transfer to a small bowl to cool slightly.
Meanwhile, whisk together mascarpone, confectioners sugar, lemon juice, zest, vanilla, and a pinch of salt until stiff.
- Assemble tart:
Spread mascarpone mixture evenly in cooled tart shell, then top with strawberries. Drizzle Port glaze all over tart.