Instructions:
Custard Preparation:
- Heat the Milk: In a medium saucepan, heat the milk over medium heat until it just begins to simmer. Remove from heat and set aside.
- Whisk the Egg Yolks: In a separate bowl, whisk together the egg yolks, sugar, and cornstarch until smooth and pale in color.
- Temper the Egg Yolks: Slowly add a few tablespoons of the warm milk into the egg yolk mixture, whisking constantly. This will prevent the eggs from scrambling. Gradually add the rest of the milk, continuing to whisk.
- Cook the Custard: Return the mixture to the saucepan and cook over medium heat, stirring constantly until it thickens (about 5–7 minutes). Be careful not to let it boil. The custard should be smooth and creamy.
- Finish the Custard: Once thickened, remove from heat and stir in the vanilla extract and butter until fully combined. Transfer the custard to a bowl, cover with plastic wrap (pressed directly onto the surface to prevent a skin from forming), and refrigerate until chilled.
Meringue Preparation:
- Beat the Egg Whites: In a large, clean bowl, beat the egg whites and salt with an electric mixer on medium speed until soft peaks form.
- Add Sugar Gradually: Gradually add the sugar, one tablespoon at a time, while continuing to beat the egg whites. If using, add the cream of tartar to stabilize the meringue. Beat until stiff peaks form, and the meringue is glossy.
- Assemble the Dessert: Once the custard is fully chilled, spoon it into serving dishes or a large serving bowl. Top with the meringue, creating decorative peaks.
- Optional Toasting: For a toasted meringue, place the dessert under a broiler for 1–2 minutes, or use a kitchen torch to gently brown the meringue until golden.
- Serve: Serve immediately for the best contrast between the cool custard and warm meringue, or refrigerate for a chilled version.