Place the parmesan cheese into the Thermomix bowl and grate for 10 seconds, Speed 8. Set aside.
Place the vegetable stock and chopped cauliflower into the Thermomix bowl, taking care to not fill past the MAX line. Season with salt and pepper.
Assemble the lid with the splash guard (TM6) or the simmering basket on top (TM31, TM5, other thermal cookers).
Cook for 25 minutes, 100 degrees, Speed 1.
Add the butter to the Thermomix bowl and pureé for 2 minutes on Speed 8 (slowly increasing speed) or until completely smooth and creamy.
Add half of the parmesan cheese and mix for a further 30 seconds on Speed 8.
Optional: serve the soup with crispy bacon pieces and the remaining parmesan cheese.