To make the sauce, blitz the butter and the cream cheese in bursts in the microwave until soft (or on the stove top in a small sauce pan). It will only take a couple of minutes. Blend together with a whisk until smooth, slowly adding the cream until combined.
Stir in half of the grated cheese. Blitz again in the microwave in bursts of about 60 seconds (or continue cooking on the stove top) until the sauce thickens, whisking well in between. This will take about 3-4 minutes in the microwave. Don't be concerned if there are a few lumps in the sauce.
Season the white sauce with salt and pepper and allow to sit and thicken for a few minutes while you prepare the cauliflower.
Cook the cauliflower until just tender but still firm, either in the microwave, parboil or steam it. This can take about 5 minutes in the microwave but can vary. Take care pulling the cling wrap off the cauliflower if you use the microwave method, as steam can build up.
Pour the cheese sauce over the cauliflower. Sprinkle with the remaining cheese.
Bake at 180 C/360 F fan forced for 15- 20 minutes or until the cheese has melted and browned slightly.
To cook in the microwave, simply cut the cauliflower to size and place it in the dish you plan to bake it in. Cover with cling wrap and cook until just tender, which is usually around 3-5 minutes. Times will vary depending on your microwaveReduce the amount of cheese that you add if you are concerned about your dairy intake.Replace the cauliflower with broccoli and follow the exact same instructions or check out this recipe for Broccoli with Cheese Sauce.