Step by step recipe:

1. 40 min.
   Prepare 1 cauliflower, then put the florets in a large pan and cover with water by 2 cm (1").
   
   Salt, add 1 chicken stock cube and bring to the boil over medium heat.
2. 3 min.
   After 2 or 3 minutes boiling, remove about ¼ of the cauliflower. Check that it's cooked but still firm and set aside.
3. 10 min.
   Coninue cooking the rest a further 3 or 4 minutes, until the cauliflower is tender, then remove from heat and blend thoroughly.
4. 3 min.
   Mix 3 tablespoons cornflour with 3 tablespoons water, then pour this into the pan, whisking until it thickens (a few seconds).
5. 2 min.
   Put back on low heat, then add 125 ml cream and 1 knob butter. Whisk one last time to mix well.
6. 3 min.
   Finish by adding the cauliflower removed earlier. Stir gently to mix...
7. 
   ...your Du Barry soup is ready.
8. 
   This excellent soup is named after the Comtesse du Barry, the last mistress of King Louis XV of France, and dates from a time when new dishes were often associated with a famous person.