Cauliflower foam

Clean the cauliflower and the onion, cut them and boil them in water and salt for about 10 minutes. Drain it.

To prepare the sauce, put the butter with the cauliflower and crush everything with the fork until get a homogeneous paste.

Next add the milk and put everything in the blender until it is very thick. Add the grated cheese while stirring until all the cheese has been melted and get a homogeneous paste. Finally add the cauliflower to the sauce, a spoonful of mustard powder, a pinch of parsley and a pinch of white pepper and beat it all together, until you get a fine puree.