01 - Blend flour, powdered sugar, and salt in a food processor. Add cold butter cubes 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 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 tart 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, whole eggs, egg yolks, sugar, and lime juice in saucepan. Cook over medium-low heat, stirring constantly, until mixture thickens and coats back of spoon, about 10 minutes. Remove from heat and stir in butter cubes until melted and smooth. Strain curd through fine mesh sieve for silky texture.
04 - Pour mango curd into cooled tart shell and spread evenly. Refrigerate for at least 1.5 hours until completely set.
05 - Top with fresh mango slices, toasted coconut flakes, and mint leaves before serving.