Will it detract from the cauliflower flavor if I use homemade vegetable stock instead of water?

Curious as to why you'd go with stock when you can use water. Sometimes, I think you get the cleanest flavor that way. I was watching The Chew the other day, and Mario Batali made a cauliflower soup with water for that very reason.

The point of this lovely soup is that, following typical holiday excesses, it's assembly and flavors are simple and clean. To be honest, I also thaw a container of vegetable stock from the freezer to use. It's heavenly.

I have not made this yet, but it's on my short list. I was reading the comments (I so love reading them) and a lot of oeople used chicken stock and a few used veg broth and one used lobster stock. They all loved the soup. As long as your veg stock isn't super strong flavored with something like broccoli, I think you should try it. I am a huge fan of following the recipe as written the first time, but I would be tempted to use at least part homemade veg or chicken stock. And there ya have my 2 cents. :0)