Melt the butter in a pan, add garlic, ginger and onions, fry until soft.
Mix all dried ingredients including xanthan gum and add to pan. Fry for a few minutes, stirring constantly.
Add stock, bring to boil, then simmer for a few minutes.
Whizz up in a blender until smooth, return to pan and continue simmering for a few minutes or until the thickness you desire.
Add a dash of soy sauce or tamari if required.