Place all the dry ingredients (erythritol, garlic and onion powders, salt, pepper and xanthan gum into a nutribullet -style machine or mini food processor and process until finely ground and combined. You could use a mortar and pestle for this step as well.
Add all the remaining wet ingredients and continue processing until thoroughly combined. You could use an emersion (stick) blender for this step too.
Place the final product into a sauce container or whatever kind of jar or container you like and place it in the fridge for a few hours before serving.