Cauliflower baked in white sauce

1 whole Cauliflower, separated and blanched in a pot of boiling water.
white sauce
shredded tasty cheese

white sauce:
4 heaped tablespoons of plain flour
4 heaped tablespoons of butter
2 cups of milk
1/2 cup of water

Melt butter, add flour and combine.
Then add the milk and stir thoroughly until thickened.
I added more water today as it was a bit too thick. 
I usually use equal amount of flour and butter and then would add milk and adjust with water if need be. 

Pop the blanched cauliflower into a casserole dish, add the white sauce on top and sprinkle it with some tasty cheese, then into a 180C oven for about 10-15 minutes until the cheese has melted. 

NB. I used the water that I blanched the cauliflower in to give more taste.