1. Preheat oven to 350°F (175°C).

2. Prepare the tart shell:

– In a bowl, mix together the flour, powdered sugar, and salt.

– Cut in the cold butter until the mixture resembles coarse crumbs.

– Press the mixture evenly into a 9-inch tart pan with a removable bottom.

– Bake for 20-25 minutes until lightly golden. Remove from the oven and let cool completely.

3. Prepare the pastry cream:

– In a saucepan, heat the milk and heavy cream over medium heat until just simmering.

– In a separate bowl, whisk together the sugar, egg yolks, and cornstarch until smooth.

– Slowly pour the hot milk mixture into the egg mixture while whisking continuously.

– Return the mixture to the saucepan and cook over medium heat, stirring constantly until it thickens (about 3-5 minutes).

– Remove from heat, then stir in the vanilla extract and butter until smooth.

– Strain the cream through a sieve for extra smoothness and let it cool to room temperature.

4. Assemble the tart:

– Spread the cooled pastry cream evenly into the tart shell.

– Arrange the fresh fruits artfully on top of the cream.

– Garnish with fresh mint leaves if desired.

5. Chill the tart in the refrigerator for at least 1 hour before serving.