In a bowl, whisk 1/2 cup of the milk with the cornstarch until smooth.

In a saucepan, combine remaining milk, cream, sugar, and salt. Warm over medium heat until steaming, but don’t boil.

Whisk in the cornstarch slurry and keep whisking over medium heat. Let it bubble gently for 1 to 2 minutes.

Remove from heat and add the chopped chocolate. Let sit for 30 seconds, then whisk until smooth.

Whisk in butter and vanilla. Taste and adjust with sugar or salt if necessary.

Strain the pudding through a fine-mesh sieve into a large measuring cup with a spout, if desired.

Divide the pudding into jars or ramekins. Cover the surface with plastic wrap to avoid skin formation.

Chill until set, at least 2 hours (4 hours is ideal).

Top with whipped cream, berries, or shaved chocolate right before serving.