01 - Blend flour, powdered sugar, and salt in a food processor. Add cold butter and pulse until mixture resembles coarse breadcrumbs. Add egg yolk and 1 tablespoon cold water, pulsing until dough just comes together. Add remaining water only if necessary. Flatten into a disk, wrap tightly, and refrigerate for 1 hour.
02 - Roll chilled dough on lightly floured surface to fit 9-inch tart pan. Press dough evenly into pan, trimming excess edges. Prick base thoroughly with fork. Return to refrigerator for 15 minutes. Preheat oven to 350°F.
03 - Line tart shell with parchment paper and fill with baking weights or dried beans. Bake for 15 minutes. Remove weights and parchment, continue baking for 10 minutes until golden brown. Cool completely before filling.
04 - Whisk mango puree, whole eggs, egg yolks, sugar, and lime juice in saucepan over medium-low heat. Stir constantly for 8-10 minutes until mixture thickens enough to coat spoon back. Remove from heat immediately.
05 - Stir butter cubes into hot curd until melted and smooth. Strain through fine mesh sieve for silken texture. Transfer to clean bowl and cool slightly.
06 - Pour slightly cooled curd into completely cooled tart shell. Smooth top with offset spatula. Refrigerate uncovered for at least 1.5 hours until fully set.
07 - Arrange fresh mango slices, toasted coconut flakes, and mint leaves on surface before serving. Slice with sharp knife, wiping blade between cuts.