Pastry Cream Instructions

• Place a fine mesh sieve over the top of a large heatproof bowl, preferably metal, you'll see why later.
• Separate the eggs and set aside
• Combine the milk, pistachio extract, and salt in a medium, heavy-bottomed sauce pan and over low-medium heat. Bring the mixture to a simmer, whisking occasionally.
• While the milk is heating up, combine the sugar, egg yolks and cornstarch in a large bowl and whisk to combine, Go overboard and really give your forearms a workout, switching between your left and right hand when one gets tired. The mix will seem too thick initially but will thin out the more you whisk it, around 2 minutes
• Using a ladle and whisking constantly, add around half of the hot milk mixture to the egg yolk mixture. This tempers the egg yolk mixture so when you add it back to the pan, it doesn't cook the egg yolks.
• Whisking the hot milk mixture constantly, pour the egg mixture back into the saucepan.
• Continue to constantly whisk the mixture in the pan and increase heat to medium. Cook for around 3 minutes or until the mixture holds the marks of the whisk and has thickened up to the consistency of pudding. If you stop whisking for a few seconds, the mixture should start bubbling.
• At this point, remove the pan from the heat and transfer the mixture to the fine mesh sieve you set up earlier. Using the whisk, press the mixture through the sieve, discarding any solids.
• Whisk the butter into the mixture, one piece at a time until smooth. If the mixture cools too much and the butter isn't melting, place the (hopefully) metal bowl over the stove top on very low heat. Whisk constantly to bring the temperature of the pastry cream up enough to melt the remainder of the butter.
• Transfer the pastry cream to a storage container and place a piece of cling film directly on top of the pastry cream to prevent a film from forming. Place in the fridge until cold, at least 4 hours.
• Once cold, combine the sour cream with the pastry cream in a large bowl and whisk until smooth.
• Transfer the pastry cream to pastry bag with a 1/4" round pastry tip.
• Shake the bag a few times to get any air bubbles out and store in the fridge until ready to use.