preheat your oven to 350°F and set aside a small baking pan (9x9)
cook the cauliflower florets for 5 minutes in boiling salted water or for 3-4 minutes in the microwave, drain and fill into the pan
heat up a pan over medium low heat and melt the butter
stir in the flour and cook for 1-2 minutes until small bubbles show
now add the sour cream & pour in a third of the milk and whisk until the sauce is smooth
add remaining milk and heavy cream and bring to a boil while stirring continuously
cook for 3-4 minutes to get rid of the floury taste
add pepper and the parmesan cheese and cook another 1-2 minutes until the cheese has melted
add salt to taste and pour over the cauliflower
spread grated cheese over it and bake for 20-30 minutes until cheese is melted and sauce is bubbly & serve hot
ENJOY!