01 - Combine flour, sugar, and salt in a bowl. Cut in cold butter until mixture resembles coarse crumbs. Add egg yolk and 2 tablespoons cold water; mix until dough forms, adding more water if necessary. Shape into disk, wrap, and chill for 30 minutes.
02 - Preheat oven to 375°F. Roll out dough on a floured surface to fit a 9-inch tart pan. Press dough into pan and trim edges. Prick base with a fork, line with parchment paper, and fill with pie weights. Bake 20 minutes, remove weights and parchment, then bake 10 to 15 minutes more until golden. Cool completely.
03 - Heat milk in a saucepan until steaming. Whisk egg yolks, sugar, and cornstarch until smooth. Gradually add hot milk to egg mixture, whisking continuously. Return to saucepan and cook over medium heat, stirring constantly, until thickened, about 3 minutes. Remove from heat, stir in butter and vanilla. Cover surface with plastic wrap and cool completely.
04 - Spread cooled pastry cream evenly in the pastry shell. Decoratively arrange pear, apple, grapes, pomegranate arils, kiwi, and orange segments on top.
05 - Heat apricot jam and water until melted and smooth. Strain if desired. Brush gently over fruit topping to add shine.
06 - Refrigerate tart for at least 1 hour to set before serving.