Brown the ground beef then drain the fat and set aside. Cook butter and onions in the same pot until translucent and fragrant.
Add broth, cauliflower, Worcestershire sauce, and seasonings, then stir and cover. Cook 15 minutes then add ground beef, cream cheese, heavy cream, and cheese.
For thick soup: Scoop out a couple tablespoons of the soup and add it to the bowl with the xanthan gum. Stir until thick, then add back to the pot.