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 remaining water only if necessary. Flatten dough into a disk, wrap in plastic, and refrigerate for minimum 1 hour.
02 - Roll chilled dough on lightly floured surface to fit 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 paper, fill with baking weights, and bake for 15 minutes. Remove weights and paper, then bake additional 10 minutes until golden brown. Cool completely.
03 - Whisk mango puree, eggs, egg yolks, sugar, and lime juice in saucepan. Cook over medium-low heat, stirring constantly, for approximately 10 minutes until thickened enough to coat back of spoon. Remove from heat and stir in butter cubes until melted and smooth. Strain curd through fine mesh sieve for silky texture.
04 - Pour cooled mango curd into pre-baked tart shell, smoothing top with spatula. Refrigerate for minimum 1.5 hours until completely set.
05 - Arrange fresh mango slices, toasted coconut flakes, and mint leaves on top of chilled tart just before serving.