Roughly chop the cauliflower and put it in the pan.
Peel the onions, also chop them coarsely and add them to the rest.
Put the vegetables in a cast iron casserole or pot and lightly brown them with a drizzle of truffle oil.
When they begin to brown, add the water (or broth), milk, thyme leaves, cover and cook for 30 minutes.
Then pour into your blender.
Add the liquid cream, salt, pepper and mix at full power until you obtain a very creamy cauliflower velouté.
Serve in bowls with a drizzle of truffle oil on top.
Add a few slices of summer truffle on top.
Then add a turn of ground pepper, a pinch of fleur de sel and serve your cauliflower velouté.