Break the cauliflower into large bouquets and boiling water until it begins to soften.
Drain and put it in a heat-resistant oven pan.
Melt the butter in a pan, add the flour and cook on low heat for 1 minute, while stirring.
Take off the heat and gradually add the milk.
Put it back on the fire, and simmer until thickened.
Add the cheese and season.
Mix until you get a homogenous béchamel sauce.
Pour the sauce over the cauliflower bouquets and sprinkle some cheese on top.
Bake in the oven until the cheese is lightly browned.