01 - In a food processor, blend flour, powdered sugar, and salt. Add butter and pulse until mixture resembles breadcrumbs. Add egg yolk and 1 tbsp cold water. Pulse until dough just comes together, adding more water if needed. Flatten into a disk, wrap in plastic, and chill for at least 1 hour.
02 - Roll out dough on lightly floured surface to fit a 9-inch tart pan. Press dough into pan and trim edges. Prick base with fork. Chill shell for 15 minutes. Preheat oven to 350°F.
03 - Line tart shell with parchment paper and fill with baking weights. Bake for 15 minutes, remove weights and paper, and bake for another 10 minutes until golden. Let cool completely.
04 - In a saucepan, whisk together mango puree, eggs, egg yolks, sugar, and lime juice. Place over medium-low heat, stirring constantly, until thickened (about 10 minutes, mixture should coat back of spoon). Remove from heat. Stir in butter cubes until smooth. Pass through fine sieve for extra smoothness.
05 - Pour curd into cooled tart shell, smoothing top. Chill in refrigerator for at least 1.5 hours, until set.
06 - Arrange fresh mango slices, toasted coconut, and mint leaves on top before serving, if desired.