You can leave out the xanthan gum if you use double cream, as I have. I suggest drying the zucchini (courgette) as well as you can after you slice it, just to get as much moisture out as possible.
It was nice, but not much flavour for how rich it is. If I make it again, I'll add herbs and more garlic, or maybe make it spicy. I think just about any flavours would work.
