Combine Greek yogurt, almond milk, whey protein isolate, sweetener, vanilla extract, and xanthan gum in a high-speed blender container.
Emulsify on medium-high speed for 60 seconds until the mixture is homogeneous and slightly aerated.
Pour the liquid base into a shallow freezer-safe container or an automated ice cream churner.
If using a churner, process for 20 minutes until it reaches a soft-serve consistency.
If still-freezing, place in the freezer and manually agitate the mixture with a whisk every 30 minutes for a duration of 2 hours to prevent macro-crystal formation.
Allow the product to set in the freezer for at least 4 hours before serving at a target temperature of -12 degrees Celsius.