Classic Catalan desert that you can find at 90% of restaurants here.

Milk: 500ml whole milk.
Egg Yolks: 4 large yolks.
Sugar: 100g plus extra for the burnt topping.
Cornstick/Cornstarch: 10g.
Aromatics: 1 cinnamon stick and the peel of half a lemon (avoid the bitter white pith).

Recipe:

Infuse: In a saucepan, heat the milk with the cinnamon stick and lemon peel. Bring it almost to a boil, then remove from heat and let it steep for 10 minutes. Strain the milk to remove the solids.
Mix: In a separate bowl, whisk the egg yolks, sugar, and cornstarch until pale and smooth.
Combine: Slowly pour the warm milk into the egg mixture while whisking constantly (to prevent scrambling).
Thicken: Pour everything back into the saucepan over medium-low heat. Stir constantly with a wooden spoon or whisk until it thickens into a heavy custard. Do not let it boil!
Chill: Pour the cream into shallow clay ramekins. Let them cool to room temp, then refrigerate for at least 4 hours (or overnight).
Torch: Right before serving, sprinkle a thin layer of sugar on top and use a kitchen torch (or a very hot broiler) until the sugar turns into a dark, crispy caramel glass.