Preheat the oven to 200 Deg C.
Grease a 6*4 inch baking tray.
Grease the baking tray with butter.
Cook the cauliflower in boiling water for 4-5 minutes.
Drain and keep aside.
In a heavy bottom pan, add in the butter.
Once slightly melted add the flour and mix it. Do this quickly and on medium, not allowing the flour to burn.
Now add the milk and salt and cook the mixture on slow to medium stirring continuously.
After 1-2 minutes, add pepper and keep stirring continuously on medium so that it does not stick to the bottom.
Once it slightly thickens add in the cheese and mix.
Switch off and assemble everything.
In the baking dish, add in the cauliflower.
Pour the white sauce on the cauliflower and bake it for 20 minutes.
For the last 5-10 minutes broil it (i.e. only using the top grill for baking).
Remove and let it rest for 5 minutes.
Enjoy it hot.