Shell pistachios and add them to milk in a jar with a lid. Close and put in the refrigerator. Keep it there for about 24-48 hours.
You will use the milk but the nuts will be soggy so it won't taste good in pudding. You can discard the soaked nuts or add it to pancakes.
Cooking Pistachio Pudding:
In a medium sauce pot, over medium heat, heat up milk, heavy cream and vanilla extract to 160℉ degrees. Turn off heat and stir well. (Remember, heat up, don't boil.)
Combine sugar, salt, flour and cornstarch in a medium mixing bowl, stir until all incorporated and set aside.
In a large metal mixing bowl, whisk egg yolks.
Very slowly, while constantly stirring, pour ½ cup of hot milk mixture into the eggs.
Pour in another ½ cup of hot milk mixture, very slowly, keep whisking.
Slowly, whisk in dry ingredients.
Turn on the heat to medium-low, pour mixture from the mixing bowl back into the sauce pot, stirring constantly.
Cook over medium to medium-low heat, slow-stirring but constantly, until mixture is thick. Remove from heat and cool to room temperature. (You can transfer it to a glass bowl of keep it in a pot of heat.)
Let The Pudding Set:
Mix in chopped pistachios, if using. Let the pudding cool to room temperature throughout before refrigerating.
Transfer into a container with an air-tight lid and refrigerate until completely cold, about 2 hours. (You can also use a bowl and plastic wrap.)
Notes
*Gluten Free Note: I often use all purpose gluten free flour to make this pudding. Note that because pudding cooks so fast, the gluten free flour doesn’t get much time to cook so the pudding may have a little graininess to it. But, those of us who have to eat gluten free are already used to a little grain once in a while.
Lactose free or Dairy Free Notes: You can make it lactose free by using lactose free half and half and increase the amount of cornstarch slightly. Also, be sure to use lactose free whole milk. To make it dairy free, you can use oat milk or almond milk to make the pistachio milk and use a plant based heavy whipping cream. Note that heavy plant based whipping cream is not always available at some grocery stores. If you can’t find any, you can use plant based half and half or unsweetened creamer. These ingredients just make a richer, creamier pudding.