Wash the cauliflower florets under cold running water. Put into a saucepan and cover with freshly boiled, filteret water.
Bring to the boil, then lower the heat and simmer, uncovered, for 8-10 minutes or until tender. Purée to a smooth texture in a blender or food processor, adding some of the cooking liquid to get the right consistency.
Spoon the mixture into ice cuve trays and freeze it.