Heat the milk in a cup in the microwave on HIGH for 2 minutes.
Whisk the egg yolks with the sugar in a bowl.
Add the cornstarch (cornflour), still whisking.
Pour the boiling milk over in a thin stream, whisking constantly.
Microwave on HIGH for 1 minute.
Microwave on HIGH for 1 further minute.
Add any flavorings (liqueur, almond, coffee, vanilla) after cooking.
To obtain a fluffy cream, add 2 egg whites beaten to firm peaks.