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 more water only if necessary. Flatten dough into a disk, wrap in plastic, and refrigerate for at least 1 hour.
02 - Roll chilled dough on a lightly floured surface to fit a 9-inch tart pan. Press dough into pan, trim edges, and prick base with fork. Refrigerate shell for 15 minutes. Preheat oven to 350°F. Line shell with parchment and fill with baking weights. Bake for 15 minutes, remove weights and paper, then bake 10 more minutes until golden. Cool completely.
03 - Whisk mango puree, eggs, egg yolks, sugar, and lime juice in a saucepan. Cook over medium-low heat, stirring constantly, for approximately 10 minutes until mixture thickens enough to coat the back of a spoon. Remove from heat and stir in butter until melted and smooth. Strain curd through fine mesh sieve for silky texture.
04 - Pour mango curd into cooled tart shell, smoothing top evenly. Refrigerate for at least 1.5 hours until completely set.
05 - Arrange fresh mango slices, toasted coconut flakes, and mint leaves on top just before serving. Serve chilled.