In a medium bowl, whisk the 3 egg yolks, 1/4 cup granulated sugar, and 1 pinch kosher salt until smooth and the sugar is mostly dissolved.
Add the 1 1/4 cups whole milk and 3/4 cup heavy cream to the yolk mixture and whisk until fully combined.
Pour the mixture into a saucepan and set over medium-low heat. Whisk constantly and heat until the mixture is hot, steaming, and slightly thickened with small bubbles forming at the edges—do not let it boil.
Remove the saucepan from the heat immediately to avoid curdling. Stir in the 1 1/2 teaspoons vanilla extract.
Place 1 cup semisweet chocolate chips in a heatproof bowl. Pour the hot custard over the chocolate chips and let sit 1 minute, then whisk until the chocolate is completely melted and the custard is smooth.
Pour the custard into individual serving cups or a large bowl. Press plastic wrap directly onto the surface of the custard to prevent a skin from forming. Refrigerate for at least 4 hours, or until set.
Garnish with fresh fruit, if desired, and serve chilled.