Step 1

Begin by heating up the cream, citrus zest and cinnamon stick on low heat in the small saucepan and stirring occasionally. When the cream begins to boil (foam) turn off the heat and let the ingredients infuse (about 30 minutes).

Step 2

In the meantime, prepare your pressure cooker by adding two cups of water, and steamer basket. Set aside.

Step 3

In a mixing bowl, add the egg yolks and sugar, whisk until the sugar is dissolved.

Step 4

Then, when the cream has cooled to room temperature (it should feel neither hot nor cold when you stick your finger in it) add the yolks and stir with your whisk just enough to get everything mixed together well (do not whip).

Step 5

Next, pour the mixture slowly through a strainer into a spouted container (if you have one, it will make pouring the mixture into the cups or ramekins easy).

Step 6

Pour the mixture into ramekins, cover tightly with foil and arrange in the steamer basket so that all are sitting straight (otherwise you will get a crooked diagonal crema).

Step 7

If you still have some vertical space and extra cups, you can stack the additional cups on top in a second layer.

Step 8

Close and lock the pressure cooker. Turn the heat up to high and calculate 8 minutes cooking time for ramekins and only 5 minutes cooking time for espresso cups at LOW pressure (the time will vary according to the size and material of the ramekin used)..

Step 9

When time is up, open the pressure cooker using the Natural Release method - move the cooker to cold burner and don't do anything. Wait for the pressure to come down naturally (about 10 minutes). For electric pressure cookers, cancel or unplug the cooker to disengage the "keep warm" cycle and count 10 minutes of time and then release the rest of the pressure using the valve.

Step 10

Open the pressure cooker and carefully lift out the custards. Open the first and jiggle it a bit. It should be nearly solid, but not liquid (this means they have set)- they will solidify further when chilled. If they are still very liquid, pressure cook for an additional 5 minutes with the same opening procedure noted above.

Step 11

Remove the custards and leave to cool uncovered for about 30-45 minutes.

Step 12

Once the custards are cooled, cover them in plastic wrap and place them in the refrigerator to chill for 3-4 hours or overnight.

Step 13

Before serving, remove the custards from the refrigerator, grate a little nutmeg and sprinkle the top of the custard with a thin, even layer of sugar.

Step 14

Then, either melt the sugar with a culinary torch or slide them under the broiler in your oven to melt and caramellize the sugar.

Step 15

Yields 10 Espresso cups, 6 Ramekins or 4-6 cazuelas (depending on their size).