In a blender, combine the pistachios and almond milk and blend until smooth.
Add in heavy cream, sweetener, vanilla extract, and salt, blending until fully combined.
Pour the mixture into a Ninja Creami pint container and freeze for 24 hours.
Once frozen, place the container in the Ninja Creami, select 'Ice Cream' mode, and let the machine churn.
If the consistency is too thick, add a splash of almond milk and re-blend.
Serve and enjoy your sugar-free pistachio ice cream!