Makes 6 servings
4 cups (1 L) whole milk
2-inch (5-cm) strip lemon zest
1 cinnamon stick
1/4 tsp (1.25 ml) salt
3/4 cup (180 ml) granulated sugar
4 large eggs, separated
1/4 cup (60 ml) cornstarch
1 tsp (5 ml) vanilla extract
Ground cinnamon, for garnish (optional)
Ground nutmeg, for garnish (optional)
Shortbread cookies or fruit (optional)
Pour 1/2 cup of milk into a medium mixing bowl. Add the egg yolks and cornstarch to the same bowl and whisk well.
Continue whisking until the mixture seems smooth and the contents are evenly distributed.
Pour the remaining milk in a medium saucepan. Add the lemon zest, sugar, cinnamon stick, and salt to the same saucepan, then set the pan on your stove over medium-low heat.
Mix the contents of the saucepan slowly and continuously as they heat up and do not use a higher heat setting. Milk burns and sticks to pans easily, so continuous motion and low heat are both necessities.
Continue heating and stirring until the mixture becomes hot but do not allow it to reach a boil yet. This step should take several minutes.
Slowly pour the egg yolk mixture into the hot milk mixture, mixing the two together constantly to combine them.
Continue stirring and heating the mixture over medium-low heat until it boils. After it begins to boil, continue whisking it for 2 minutes or longer.
Test the taste of the Natillas after the first 2 minutes. If you can detect the taste of cornstarch, you'll need to continue heating the mixture for another minute or so. If the cornstarch taste is gone, you can proceed to the next step.
Remove the saucepan from the stove. Take out the lemon zest and cinnamon stick, then add the vanilla extract, stirring it in until evenly distributed.
In a separate bowl, beat the egg whites using an electric mixer set to low speed, continuing until stiff peaks form.
When the egg whites are ready, stiff peaks should form when you lift the mixer out. These peaks should stand sharply without drooping.
Note that the addition of egg whites is mostly found in Mexican versions of Natillas. Many traditional Spanish versions do not use egg whites, and the result is a much denser custard. As such, you may omit the egg whites altogether if desired.
Fold the egg whites into the custard. Top the custard in your saucepan with the stiff egg whites. Carefully fold the egg white into the custard with a spatula until no visible streaks of white remain.
Fold carefully, applying as little pressure as possible to the egg whites during the process. Working too quickly or with too much force can cause the egg whites to lose most of the air you just beat into them.
Chill for a minimum of 3 hours. Carefully press a sheet of plastic wrap over the surface of the natillas, then place the saucepan in your refrigerator until the custard is cool and semi-set.
If you want to serve the Natillas in individual custard cups, you should pour the mixture into the cups while it is still warm.
Serve when ready. After the Natillas have cooled and set, scoop the custard into individual serving dishes and sprinkle each one with ground cinnamon or ground nutmeg.
Alternatively, you could top each helping of Natillas with a shortbread cookie or brulee fruit.
You should be able to store Natillas in sealed containers for 3 days inside your refrigerator.
Chef Martin Lopez