Mix the granulated sugar, cornstarch, and a pinch of Kosher salt in a large sauce pan. Add the egg yolks and whisk the mixture until it's thick and lightened in color, about 2-3 minutes. Slowly whisk in the whole milk until smooth.

Place the pot on the stove over medium heat. Cook, whisking constantly, until the mixture comes to a boil. Boil for 1-2 minutes, just until the pastry cream is thick like pudding.

Immediately strain the pastry cream through a fine-mesh sieve to remove any lumps. Add the cold butter cubes and vanilla bean paste or vanilla extract. Stir until the butter is melted and the custard is creamy and smooth.

Press a piece of plastic wrap to the top of the pastry cream to keep a skin from forming. Let the pastry cream cool at room temperature, about 30-60 minutes. Then, refrigerate until it's completely chilled.

Cut the stems off of the strawberries. Then, dice the strawberries into small chunks.

When the pastry cream is chilled, use a spoon or pastry bag to divide it evenly between the 32 tart shells. Top each tart with a generous spoonful of strawberries.

Next, microwave the apricot preserves in a small bowl until it's runny, about 20-30 seconds. Use a pastry brush to brush the strawberries with the apricot glaze. Serve the tartlets immediately or refrigerate for up to 2 hours before serving. Enjoy!