Heat oil and saute onion and garlic.
Once onion is clear, add the stock and cauliflower and slowly bring to the boil.
Reduce to a simmer and add the rosemary sprigs (if you don't like the pieces of rosemary in the soup, add within a mesh cooking bag to keep together).
Once cooked through and the rosemary has added enough flavour, remove the sprigs.
Puree with a stick blender or the like.
Nutritional yeast can be added on serving to help thicken the soup if needed.
Onions can be pre-roasted to add more depth and you can also add coconut cream for that extra creamy texture.
Enjoy!