In a food processor, combine all-purpose flour, powdered sugar, and cold butter. Pulse until the mixture resembles coarse sand. Then, add a room temperature egg and pulse until a dough forms.

Shape the dough into a ball and roll it out to about ⅛ inch thickness between two sheets of parchment paper. Wrap in plastic wrap and chill in the refrigerator for at least 1 hour.

Once chilled, remove the dough, cut out 3-inch rounds, and press into mini tart shells. Prick the bottom of each crust with a fork and chill for an additional hour.

Preheat your oven to 325°F (160°C) while the crusts chill.

Line the tart shells with parchment paper and fill with baking weights. Bake for 12 minutes, then remove weights and parchment. Continue baking for another 8-10 minutes until golden brown.

In a saucepan over medium heat, whisk together kiwi juice, egg yolks, sugar, lime juice, and lime zest. Cook while stirring frequently for about 15 minutes or until thickened.

Once thickened, remove from heat and whisk in room temperature butter until smooth.

Pour the warm kiwi lime curd into the cooled tart crusts and refrigerate for at least 2 hours to set.

Top each tart with thinly sliced fresh kiwi just before serving. Let the tarts sit at room temperature for 30 minutes.